[HLSL][Matrix] Add Matrix splat support for booleans (#175809)
Fixes #175808
This PR adds support for boolean matrix splats by adding tests and
fixing a bug in `CodeGenFunction::EmitToMemory` when the type of a
boolean matrix already matches the type expected of a load/store.
This PR also addresses the todo comment in `clang/lib/Sema/SemaExpr.cpp`
regarding support for boolean matrix splats by removing the comment
altogether since it is not necessary.
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Co-authored-by: Farzon Lotfi <farzonlotfi@microsoft.com>