[CUDA] Enable variadic argument support in front-end (#161305)

Variadice argument for NVPTX as been support in

486d00e
We can enable it in front-end.

Co-authored-by: Yuanke Luo <[email protected]>

Author: LuoYuanke

clang/lib/Sema/SemaExpr.cpp

@@ -16791,12 +16791,11 @@ ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc,
   Expr *OrigExpr = E;
   bool IsMS = false;
 
-  // CUDA device code does not support varargs.
+  // CUDA device global function does not support varargs.
   if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice) {
     if (const FunctionDecl *F = dyn_cast<FunctionDecl>(CurContext)) {
       CUDAFunctionTarget T = CUDA().IdentifyTarget(F);
-      if (T == CUDAFunctionTarget::Global || T == CUDAFunctionTarget::Device ||
-          T == CUDAFunctionTarget::HostDevice)
+      if (T == CUDAFunctionTarget::Global)
         return ExprError(Diag(E->getBeginLoc(), diag::err_va_arg_in_device));
     }
   }

clang/test/SemaCUDA/vararg.cu

@@ -10,7 +10,7 @@
 #include <stdarg.h>
 #include "Inputs/cuda.h"
 
-__device__ void foo() {
+__global__ void foo() {
   va_list list;
   va_arg(list, int);
 #ifdef EXPECT_VA_ARG_ERR