[clang] [HLSL][Matrix] Update indexed matrix elements individually (PR #176216)

[Joshua Batista via cfe-commits]

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@@ -2772,6 +2804,7 @@ void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
                 ->getNumElements();
       }
 
+      llvm::Value *Row = Dst.getMatrixRowIdx();
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bob80905 wrote:

Not sure, just curious. Is it possible to repeat that same OptLevel > 0, index assumption logic here and apply it to rows?

https://github.com/llvm/llvm-project/pull/176216