[llvm] [clang] [RISCV][Clang][TargetParser] Support getting feature unaligned-scalar-mem from mcpu. (PR #71513)

[Yeting Kuo via cfe-commits]

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@@ -44,6 +45,11 @@ static const CPUInfo *getCPUInfoByName(StringRef CPU) {
   return nullptr;
 }
 
+bool hasFastUnalignedAccess(StringRef CPU) {
+  const CPUInfo *Info = getCPUInfoByName(CPU);
+  return Info && Info->FastUnalignedAccess;
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yetingk wrote:

It's possible that `Info` is `nullptr` here when CPU is not defined in `RISCVProcessors.td`.

https://github.com/llvm/llvm-project/pull/71513