[clang] [clang][HLSL] Add GroupMemoryBarrierWithGroupSync intrinsic (PR #111883)

[Finn Plummer via cfe-commits]

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+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -emit-llvm-only -disable-llvm-passes -verify -verify-ignore-unexpected
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inbelic wrote:

Will forward this comment here about `-verify-ignore-unexpected`: https://github.com/llvm/llvm-project/pull/111209#discussion_r1793906097

https://github.com/llvm/llvm-project/pull/111883