[clang] [HLSL][SPIR-V] Fix clang driver lang target test (PR #70330)

[Natalie Chouinard via cfe-commits]

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@@ -2,8 +2,8 @@
 
 // Supported targets
 //
-// RUN: %clang -target dxil-unknown-shadermodel6.2-pixel %s -S -o /dev/null 2>&1 | FileCheck --check-prefix=CHECK-VALID %s
-// RUN: %clang -target spirv-unknown-shadermodel6.2-library %s -S -o /dev/null 2>&1 | FileCheck --check-prefix=CHECK-VALID %s
+// RUN: %clang -target dxil-unknown-shadermodel6.2-compute %s -S -o /dev/null 2>&1 | FileCheck --allow-empty --check-prefix=CHECK-VALID %s
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sudonatalie wrote:

`FileCheck` fails by default when the input is empty, which is the case when this test succeeds (the actual compilation output is being sent to `/dev/null`, just stdout/stderr messages are checked). The dxil case was succeeding because there's always the `clang: warning: dxv not found. Resulting DXIL will not be validated or signed for use in release environments.` message, but since that's not the thing this test is checking I figured it made more sense to `--allow-empty` for both.

https://github.com/llvm/llvm-project/pull/70330