[OpenCL] No need to check array of struct for kernel arguments (#138894)

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

@@ -9725,14 +9725,10 @@ 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 {
@@ -9797,8 +9793,8 @@ 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