[clang] [HLSL][Driver][SPIRV] Add -fspv-use-legacy-buffer-matrix-order flag (PR #214575)

[Farzon Lotfi via cfe-commits]

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farzonl wrote:

Instead of Doing `AddLoads` and `AddStore` below we are redirecting the generic case through a builtin so we can give CodeGen a hook to intercept matrix values. That way we can know if we should do a transpose or not for loads and stores when given the spv flag.

https://github.com/llvm/llvm-project/pull/214575