[CUDA] Simplify GPU variant handling. NFC.

Instead of hardcoding individual GPU mappings in multiple functions, keep them
all in one table and use it to look up the mappings.

We also don't care about 'virtual' architecture much, so the API is trimmed down
down to a simpler GPU->Virtual arch name lookup.

Differential Revision: https://reviews.llvm.org/D77665

Author: Artem-B

clang/include/clang/Basic/Cuda.h

@@ -72,36 +72,20 @@ enum class CudaArch {
   GFX1012,
   LAST,
 };
-const char *CudaArchToString(CudaArch A);
 
-// The input should have the form "sm_20".
-CudaArch StringToCudaArch(llvm::StringRef S);
+static inline bool IsNVIDIAGpuArch(CudaArch A) {
+  return A >= CudaArch::SM_20 && A < CudaArch::GFX600;
+}
 
-enum class CudaVirtualArch {
-  UNKNOWN,
-  COMPUTE_20,
-  COMPUTE_30,
-  COMPUTE_32,
-  COMPUTE_35,
-  COMPUTE_37,
-  COMPUTE_50,
-  COMPUTE_52,
-  COMPUTE_53,
-  COMPUTE_60,
-  COMPUTE_61,
-  COMPUTE_62,
-  COMPUTE_70,
-  COMPUTE_72,
-  COMPUTE_75,
-  COMPUTE_AMDGCN,
-};
-const char *CudaVirtualArchToString(CudaVirtualArch A);
+static inline bool IsAMDGpuArch(CudaArch A) {
+  return A >= CudaArch::GFX600 && A < CudaArch::LAST;
+}
 
-// The input should have the form "compute_20".
-CudaVirtualArch StringToCudaVirtualArch(llvm::StringRef S);
+const char *CudaArchToString(CudaArch A);
+const char *CudaArchToVirtualArchString(CudaArch A);
 
-/// Get the compute_xx corresponding to an sm_yy.
-CudaVirtualArch VirtualArchForCudaArch(CudaArch A);
+// The input should have the form "sm_20".
+CudaArch StringToCudaArch(llvm::StringRef S);
 
 /// Get the earliest CudaVersion that supports the given CudaArch.
 CudaVersion MinVersionForCudaArch(CudaArch A);