[clang] [HLSL] Simplify test (PR #165743)

[Justin Bogner via cfe-commits]

bogner wrote:

> oh i thought this change did preserve that since this test should fail if such an error is produced? Or that was my thought.

IIRC the error was only happening when the clang -cc1 command with both -S and -emit-llvm present was actually run, so the -### command wouldn't produce the error on its own. That said, testing that something doesn't happen for a bug that was fixed long ago is kind of tricky business - this is probably good enough as is.

https://github.com/llvm/llvm-project/pull/165743