[clang] [Headers][X86] Add a couple of tests for MMX/SSE intrinsics (PR #105852)

[Phoebe Wang via cfe-commits]

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+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only \
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phoebewang wrote:

Move it to clang/test/CodeGen/X86?

https://github.com/llvm/llvm-project/pull/105852