[clang] [clang] Check validity of SYCL device target (PR #172366)

[Mariya Podchishchaeva via cfe-commits]

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@@ -118,6 +118,12 @@ bool CompilerInstance::createTarget() {
   if (!hasTarget())
     return false;
 
+  if (getLangOpts().SYCLIsDevice && !getTarget().isValidSYCLDeviceTarget()) {
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Fznamznon wrote:

I recently discovered there is Triple::isGPU() added by 48b753027382a5815295d6680c7dd407be936c86 . Should we reuse it instead of adding `isValidSYCLDeviceTarget`?

https://github.com/llvm/llvm-project/pull/172366