[OpenCL] No need to check array of struct for kernel arguments

Since arrays decay into pointers, no need to check them for arguments.
This commit reverts part of the changes from the commit
"[OpenCL] Check for invalid kernel arguments in array types"
3b238ed.

Author: jiefwo

clang/lib/Sema/SemaDecl.cpp

@@ -9717,14 +9717,10 @@ static void checkIsValidOpenCLKernelParameter(
   SmallVector<const FieldDecl *, 4> HistoryStack;
   HistoryStack.push_back(nullptr);
 
-  // At this point we already handled everything except of a RecordType or
-  // an ArrayType of a RecordType.
-  assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type.");
-  const RecordType *RecTy =
-      PT->getPointeeOrArrayElementType()->getAs<RecordType>();
-  const RecordDecl *OrigRecDecl = RecTy->getDecl();
-
-  VisitStack.push_back(RecTy->getDecl());
+  // At this point we already handled everything except of a RecordType.
+  assert(PT->isRecordType() && "Unexpected type.");
+  const RecordDecl *PD = PT->castAs<RecordType>()->getDecl();
+  VisitStack.push_back(PD);
   assert(VisitStack.back() && "First decl null?");
 
   do {
@@ -9789,8 +9785,8 @@ static void checkIsValidOpenCLKernelParameter(
         S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
       }
 
-      S.Diag(OrigRecDecl->getLocation(), diag::note_within_field_of_type)
-          << OrigRecDecl->getDeclName();
+      S.Diag(PD->getLocation(), diag::note_within_field_of_type)
+          << PD->getDeclName();
 
       // We have an error, now let's go back up through history and show where
       // the offending field came from