[llvm] [SPIR-V] Complete SPV_INTEL_16bit_atomics extension support (PR #184312)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -0,0 +1,38 @@
+; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_KHR_bfloat16 %s -o %t.spvt 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR
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jmmartinez wrote:

I've seen tests using `/dev/null` for the output file that do not seem windows specific. So maybe since the output is not interesting we could use it here.

```suggestion
; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_KHR_bfloat16 %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR
```

https://github.com/llvm/llvm-project/pull/184312