[Matrix] Implement Clang matrix types extension

[fhahn]

Bugzilla Link	46163
Version	unspecified
OS	All
Depends On	#45596 #45509 #45510 #46485 #49082 #49083
CC	@DougGregor,@RKSimon,@zygoloid,@sjoerdmeijer

Extended Description

Issue to track outstanding tasks/issues for implementing the Matrix Types extension (https://clang.llvm.org/docs/MatrixTypes.html#matrixtypes) in Clang.

[fhahn]

mentioned in issue #45509

[fhahn]

mentioned in issue #45510

[fhahn]

mentioned in issue #45596

[fhahn]

mentioned in issue #46485

[fhahn]

mentioned in issue #49082

[fhahn]

mentioned in issue #49083