[llvm] [SPIRV] Change how to detect OpenCL/Vulkan Env and update tests accordingly. (PR #129689)

[Nathan Gauër via llvm-commits]

================
@@ -112,7 +120,7 @@ bool SPIRVSubtarget::canUseExtInstSet(
 
 SPIRV::InstructionSet::InstructionSet
 SPIRVSubtarget::getPreferredInstructionSet() const {
-  if (isOpenCLEnv())
+  if (!isShaderEnv())
----------------
Keenuts wrote:

```suggestion
  if (isKernelEnv())
```

https://github.com/llvm/llvm-project/pull/129689