[clang] [llvm] Add InterlockedAdd resource methods (PR #208128)

[Farzon Lotfi via cfe-commits]

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@@ -61,6 +61,14 @@ def int_dx_resource_store_rawbuffer
     : DefaultAttrsIntrinsic<
           [], [llvm_any_ty, llvm_i32_ty, llvm_i32_ty, llvm_any_ty],
           [IntrWriteMem]>;
+// Resource atomic binary op: performs an atomic read-modify-write on a UAV
+// resource element and returns the original value. The i32 operation code
+// matches DXIL's AtomicBinOpCode enum.
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farzonl wrote:

We have not done much commenting of intrinsics i don't know why we are doing it for this one. Also this is another case where I feel like why can't we just use the llvm instruction? 

https://github.com/llvm/llvm-project/pull/208128