[OpenCL] Fix an infinite loop in builidng AddrSpaceQualType

 In building AddrSpaceQualType (llvm#90048),
there is a bug in removeAddrSpaceQualType() for arrays. Arrays are weird because
qualifiers on the element type also count as qualifiers on the type, so
getSingleStepDesugaredType() can't remove the sugar on arrays. This results
in an infinite loop in removeAddrSpaceQualType. To fix the issue,
we use ASTContext::getUnqualifiedArrayType, which strips the qualifier off
the element type, then reconstruct the array type.

Author: changpeng

clang/lib/CodeGen/CGExprAgg.cpp

@@ -537,8 +537,9 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
       elementType.isTriviallyCopyableType(CGF.getContext())) {
     CodeGen::CodeGenModule &CGM = CGF.CGM;
     ConstantEmitter Emitter(CGF);
+    Qualifiers Quals;
     QualType GVArrayQTy = CGM.getContext().getAddrSpaceQualType(
-        CGM.getContext().removeAddrSpaceQualType(ArrayQTy),
+        CGM.getContext().getUnqualifiedArrayType(ArrayQTy, Quals),
         CGM.GetGlobalConstantAddressSpace());
     LangAS AS = GVArrayQTy.getAddressSpace();
     if (llvm::Constant *C =

clang/test/CodeGenOpenCLCXX/array-type-infinite-loop.clcpp

@@ -0,0 +1,25 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 4
+//RUN: %clang_cc1 %s -emit-llvm -O1 -o - | FileCheck %s
+
+// CHECK-LABEL: define dso_local spir_kernel void @test(
+// CHECK-SAME: ptr nocapture noundef readonly align 8 [[IN:%.*]], ptr nocapture noundef writeonly align 8 [[OUT:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] !kernel_arg_addr_space [[META3:![0-9]+]] !kernel_arg_access_qual [[META4:![0-9]+]] !kernel_arg_type [[META5:![0-9]+]] !kernel_arg_base_type [[META5]] !kernel_arg_type_qual [[META6:![0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[IN]], i64 8
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr [[ARRAYIDX1]], align 8, !tbaa [[TBAA7:![0-9]+]]
+// CHECK-NEXT:    store i64 [[TMP0]], ptr [[OUT]], align 8, !tbaa [[TBAA7]]
+// CHECK-NEXT:    ret void
+//
+__kernel void test(__global long *In, __global long *Out) {
+   long m[4] = {  In[0], In[1], 0, 0 };
+   *Out = m[1];
+}
+//.
+// CHECK: [[META3]] = !{i32 1, i32 1}
+// CHECK: [[META4]] = !{!"none", !"none"}
+// CHECK: [[META5]] = !{!"long*", !"long*"}
+// CHECK: [[META6]] = !{!"", !""}
+// CHECK: [[TBAA7]] = !{[[META8:![0-9]+]], [[META8]], i64 0}
+// CHECK: [[META8]] = !{!"long", [[META9:![0-9]+]], i64 0}
+// CHECK: [[META9]] = !{!"omnipotent char", [[META10:![0-9]+]], i64 0}
+// CHECK: [[META10]] = !{!"Simple C++ TBAA"}
+//.