[Clang][OpenCL][AMDGPU] Allow a kernel to call another kernel

Simplifying isDeclOpenCLKernel() and removing resolved comments

Author: anikelal

clang/include/clang/AST/GlobalDecl.h

@@ -213,10 +213,9 @@ class GlobalDecl {
   }
 
   bool isDeclOpenCLKernel() const {
-    auto FD = dyn_cast<FunctionDecl>(getDecl());
-    if (FD)
+    if (auto FD = dyn_cast<FunctionDecl>(getDecl()))
       return FD->hasAttr<OpenCLKernelAttr>();
-    return FD;
+    return false;
   }
 };
 

clang/lib/CodeGen/CGOpenCLRuntime.cpp

@@ -129,8 +129,6 @@ void CGOpenCLRuntime::recordBlockInfo(const BlockExpr *E,
                                       llvm::Value *Block, llvm::Type *BlockTy,
                                       bool isBlkExprInOCLKern) {
 
-  // FIXME: Since OpenCL Kernels are emitted twice (kernel version and stub
-  // version), its constituent BlockExpr will also be emitted twice.
   assert((!EnqueuedBlockMap.contains(E) ||
           EnqueuedBlockMap[E].isBlkExprInOCLKern != isBlkExprInOCLKern) &&
          "Block expression emitted twice");