[OpenCL] Fix semantic check for device_side_enqueue.

[dmitry]

Summary

Check unqualified type for ndrange argument in device_side_enqueue so
device_side_enqueue accept const and volatile qualified ndranges.

[dmitry]

@yaxunl, could you kindly review the patch? It's quite short this time.

[yaxunl]

LGTM. Thanks. Sorry for the delay.

lib/Sema/SemaChecking.cpp

static bool SemaOpenCLBuiltinEnqueueKernel(Sema &S, CallExpr *TheCall) {
   if (!Arg1->getType()->isIntegerType()) {
     S.Diag(TheCall->getArg(1)->getLocStart(),
            diag::err_opencl_enqueue_kernel_expected_type)
         << "'kernel_enqueue_flags_t' (i.e. uint)";
     return true;
   }
 
   // Third argument is always an ndrange_t type.
-  if (Arg2->getType().getAsString() != "ndrange_t") {
+  if (Arg2->getType().getUnqualifiedType().getAsString() != "ndrange_t") {
     S.Diag(TheCall->getArg(2)->getLocStart(),
            diag::err_opencl_enqueue_kernel_expected_type)
         << "'ndrange_t'";
     return true;
   }
 
   // With four arguments, there is only one form that the function could be
   // called in: no events and no variable arguments.

test/SemaOpenCL/cl20-device-side-enqueue.cl

-// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir-unknown-unknown" -verify -pedantic -fsyntax-only -DB32
-// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir64-unknown-unknown" -verify -pedantic -fsyntax-only -Wconversion -DWCONV
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir-unknown-unknown" -verify -pedantic -fsyntax-only -DB32 -DQUALS=
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir-unknown-unknown" -verify -pedantic -fsyntax-only -DB32 -DQUALS="const volatile"
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir64-unknown-unknown" -verify -pedantic -fsyntax-only -Wconversion -DWCONV -DQUALS=
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -triple "spir64-unknown-unknown" -verify -pedantic -fsyntax-only -Wconversion -DWCONV -DQUALS="const volatile"
 
 typedef struct {int a;} ndrange_t;
 // Diagnostic tests for different overloads of enqueue_kernel from Table 6.13.17.1 of OpenCL 2.0 Spec.
 kernel void enqueue_kernel_tests() {
   queue_t default_queue;
   unsigned flags = 0;
-  ndrange_t ndrange;
+  QUALS ndrange_t ndrange;
   clk_event_t evt;
   clk_event_t event_wait_list;
   clk_event_t event_wait_list2[] = {evt, evt};
   void *vptr;
 
   // Testing the first overload type
   enqueue_kernel(default_queue, flags, ndrange, ^(void) {
     return 0;