Auto require not found by extra specifier search #494

On 5.3.0, when a module defines a require on itself, when this requirement is searched the module is omitted from result:

$ cat /path/to/modulefiles/bar/1.0
#%Module
module load bar/1.0
$ module use /path/to/modulefiles
$ module avail require:bar/1.0
$

bar/1.0 should be returned by module avail in the above example.

This is not a real world use case (a module should not require itself) but it demonstrates an issue in the extra specifier search mechanism.