wasm: enforce WasmGC opt-in capability checks and Firefox < 147 guard - #193180

…flutter#193180)

Ensures that when an application opts into WebAssembly on Firefox or
Safari via `wasmAllowList` in JS/JSON bootstrap configuration,
`FlutterLoader` strictly enforces `supportsDart2Wasm()` capability
checks and browser version guards before selecting any `dart2wasm`
build:

- **Firefox `< 147` WasmGC Version Guard**: Guards `supportsDart2Wasm()`
in `browser_environment.js` so Firefox `< 147` falls back to `dart2js`
even if `wasmAllowList: { gecko: true }` is configured.
- **Unify `enableWasm` Gating Across All `dart2wasm` Targets**: Moves
the `!enableWasm` check in `loader.js` from
`rendererIncompatibilityReason('skwasm')` into
`buildIncompatibilityReason` for `build.compileTarget === 'dart2wasm'`,
preventing `dart2wasm` + `canvaskit` builds from bypassing
`wasmAllowList` opt-outs.
- **Explicit Opt-In Fallback Test**: Adds test coverage in
`fallbacks_test.dart` verifying that `flutter.loader.load()` with
`wasmAllowList` explicitly enabled for all engines still rejects
`dart2wasm` builds when `supportsDart2Wasm` is false.

Part of flutter#143603

…flutter#193180)

Ensures that when an application opts into WebAssembly on Firefox or
Safari via `wasmAllowList` in JS/JSON bootstrap configuration,
`FlutterLoader` strictly enforces `supportsDart2Wasm()` capability
checks and browser version guards before selecting any `dart2wasm`
build:

- **Firefox `< 147` WasmGC Version Guard**: Guards `supportsDart2Wasm()`
in `browser_environment.js` so Firefox `< 147` falls back to `dart2js`
even if `wasmAllowList: { gecko: true }` is configured.
- **Unify `enableWasm` Gating Across All `dart2wasm` Targets**: Moves
the `!enableWasm` check in `loader.js` from
`rendererIncompatibilityReason('skwasm')` into
`buildIncompatibilityReason` for `build.compileTarget === 'dart2wasm'`,
preventing `dart2wasm` + `canvaskit` builds from bypassing
`wasmAllowList` opt-outs.
- **Explicit Opt-In Fallback Test**: Adds test coverage in
`fallbacks_test.dart` verifying that `flutter.loader.load()` with
`wasmAllowList` explicitly enabled for all engines still rejects
`dart2wasm` builds when `supportsDart2Wasm` is false.

Part of flutter#143603

…#13060)

Manual roll Flutter from 4fcd90be0045 to c5a061b18fa2 (222 revisions)

Manual roll requested by [email protected]

flutter/flutter@4fcd90b...c5a061b

2026-09-28 [email protected] [cross imports] navigator_test.dart (flutter/flutter#190954)
2026-09-28 [email protected] Revert: Reland: Only render views that need to be rendered  (flutter/flutter#193360)
2026-09-28 [email protected] ci(bringup): android_intent_security_test is green (flutter/flutter#193469)
2026-09-28 [email protected] Sync CHANGELOG.md from stable (flutter/flutter#193020)
2026-09-28 [email protected] Roll Fuchsia Linux SDK from ukukV5lEkKabtOATk... to QdgqP02_cYpRQQQNN... (flutter/flutter#193454)
2026-09-28 [email protected] Roll pub packages (flutter/flutter#193460)
2026-09-28 [email protected] Un-nest sceneBuildDuration and windowRenderDuration in web SceneBuilderRecorder (flutter/flutter#193260)
2026-09-28 [email protected] Fix unresolved doc comment references in dev/integration_tests and dev/benchmarks (flutter/flutter#193433)
2026-09-28 [email protected] Roll Packages from e55e7ac to ba0364a (9 revisions) (flutter/flutter#193450)
2026-09-28 [email protected] [tool] Require explicit dependency injection for FlutterDevice and FlutterDevice.create (flutter/flutter#192830)
2026-09-28 [email protected] Roll pub packages (flutter/flutter#193442)
2026-09-28 [email protected] [flutter_tools] Include data assets from hooks when pubspec.yaml is empty (flutter/flutter#193434)
2026-09-28 [email protected] Roll pub packages (flutter/flutter#193438)
2026-09-28 [email protected] Fix unresolved doc comment references in Material and Cupertino (flutter/flutter#193283)
2026-09-28 [email protected] Fix doc references to Material and Cupertino in the widgets library and its tests (flutter/flutter#193334)
2026-09-26 [email protected] wasm: enforce WasmGC opt-in capability checks and Firefox < 147 guard (flutter/flutter#193180)
2026-09-26 [email protected] [Android] Refuse external setters of engine entrypoint and cached engine arguments via `Intent`s (flutter/flutter#190249)
2026-09-26 [email protected] [web] Unskip TextPainter.getWordBoundary test (flutter/flutter#193378)
2026-09-26 [email protected] Specify non-obvious types in pattern variable declarations (flutter/flutter#192632)
2026-09-26 [email protected] Removes feedback loop from advanced filters without offscreen msaa and framebufferfetch (flutter/flutter#193306)
2026-09-26 [email protected] [web] Unskip 8 passing image tests in painting and rendering (flutter/flutter#193377)
2026-09-26 [email protected] Revert: Allow resetting test invariants in `addTearDown` (flutter/flutter#193383)
2026-09-25 [email protected] [tool] Migrate CoverageCollector to modular dependency injection (flutter/flutter#192924)
2026-09-25 [email protected] Fix more unresolved doc comment references (flutter/flutter#193336)
2026-09-25 [email protected] Allow resetting test invariants in `addTearDown` (flutter/flutter#192082)
2026-09-25 [email protected] [a11y] Add a semantics role for slider (flutter/flutter#193324)
2026-09-25 [email protected] Fix plugin tests after Pigeon plugin template changes (flutter/flutter#193302)
2026-09-25 [email protected] [Android 17] Bump Standard Test Apps in flutter/flutter to AGP 9.3.1 (flutter/flutter#193263)
2026-09-25 [email protected] SSBO-based gradients in UberSDF (flutter/flutter#192962)
2026-09-25 [email protected] [Linux] Handle FlView being destroyed before rendering is complete. (flutter/flutter#193268)
2026-09-25 [email protected] [flutter_tools] Handle Windows reserved characters in test target path (flutter/flutter#191900)
2026-09-25 [email protected] docs(tools): nit: say hook/build.dart in CMake native assets comment (flutter/flutter#192205)
2026-09-25 [email protected] [web] Enable Firefox Skwasm UI CI suites, configure COI configs, and fail fast on loader rejections (flutter/flutter#193187)
2026-09-25 [email protected] [Android 17] Bumped Engine Dependencies to 9.3.1 (flutter/flutter#193265)
2026-09-25 [email protected] [web] Omit group role on menu scrollables and assign region role to named routes (flutter/flutter#192965)
2026-09-25 [email protected] Roll Skia from 8eedeed98e79 to f441ca223b2b (5 revisions) (flutter/flutter#193353)
2026-09-25 [email protected] Roll Fuchsia Linux SDK from EbPpoJW-Lnsu-8dyZ... to ukukV5lEkKabtOATk... (flutter/flutter#193326)
2026-09-25 [email protected] Roll Packages from 431ea69 to e55e7ac (6 revisions) (flutter/flutter#193351)
2026-09-25 [email protected] Support DynamicLibrary.codeAsset in Flutter (flutter/flutter#188947)
2026-09-25 [email protected] Roll Dart SDK from 75d9e87d4e3d to 0e7642b85457 (1 revision) (flutter/flutter#193346)
2026-09-25 [email protected] Exclude iOS PRs from macOS link (flutter/flutter#193315)
2026-09-25 [email protected] Roll Skia from 6357608543ec to 8eedeed98e79 (4 revisions) (flutter/flutter#193341)
2026-09-25 [email protected] Roll Dart SDK from d3aedb186aab to 75d9e87d4e3d (3 revisions) (flutter/flutter#193335)
2026-09-25 [email protected] Cache the paint offset adjusted line metrics in TextPainter (flutter/flutter#191223)
...

- Merges origin/master (resolving conflict with flutter#193180 by checking `window._flutter?.supportsDart2Wasm ?? defaultSupportsDart2Wasm()` after the Firefox < 147 guard in `browser_environment.js`).
- Raises `RuntimeError` in `create_updated_flutter_deps.py` when fetching `compile.dart` at `--dart_revision` fails or when `compile.dart` cannot be resolved.
- Updates `Skwasm` and `dart2wasm` incompatibility messages in `loader.js` to list `(WasmGC, SIMD, js-string builtins, try_table)`.

…y checks (flutter#193667)

Adds a regression test in `fallbacks_test.dart` (`firefox-fallbacks`
suite) verifying the `Firefox < 147` version gate added in flutter#193180 (and
its precedence over `_flutter.supportsDart2Wasm` in flutter#193271):

1. **Firefox 146 (`< 147`)**: Even when `wasmAllowList: { gecko: true }`
is configured, `_flutter.supportsDart2Wasm` is `true`, and
`WebAssembly.validate` returns `true`, `FlutterLoader.load` rejects
`dart2wasm` builds before invoking `WebAssembly.validate`
(`validateCalls == 0`).
2. **Firefox 147 (`>= 147`)**: Passes the Firefox version gate and
proceeds to evaluate `WebAssembly.validate` (`validateCalls > 0`).

Related to flutter#143603 and flutter#186619

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.