Remove unwanted signedness conversion from tests

[mantognini]

Summary

This is just a minor update of the tests.

[mantognini]

Note: the get_kernel_* functions used here all return unsigned integers, hence the warning/present patch.

[Anastasia]

LGTM!

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

kernel void work_group_size_tests() {
   size = get_kernel_preferred_work_group_size_multiple(block_D);   // expected-error {{blocks used in enqueue_kernel call are expected to have parameters of type 'local void*'}}
   size = get_kernel_preferred_work_group_size_multiple();          // expected-error {{too few arguments to function call, expected 1, have 0}}
   size = get_kernel_preferred_work_group_size_multiple(1);         // expected-error{{expected block argument}}
   size = get_kernel_preferred_work_group_size_multiple(block_A, 1); // expected-error{{too many arguments to function call, expected 1, have 2}}
 }
 
 #pragma OPENCL EXTENSION cl_khr_subgroups : enable
 
-kernel void foo(global int *buf)
+kernel void foo(global unsigned int *buf)
 {
   ndrange_t n;
   buf[0] = get_kernel_max_sub_group_size_for_ndrange(n, ^(){});
   buf[0] = get_kernel_max_sub_group_size_for_ndrange(0, ^(){}); // expected-error{{illegal call to 'get_kernel_max_sub_group_size_for_ndrange', expected 'ndrange_t' argument type}}
   buf[0] = get_kernel_max_sub_group_size_for_ndrange(n, 1); // expected-error{{illegal call to 'get_kernel_max_sub_group_size_for_ndrange', expected block argument type}}
 }
 
-kernel void bar(global int *buf)
+kernel void bar(global unsigned int *buf)
 {
   __private ndrange_t n;
   buf[0] = get_kernel_sub_group_count_for_ndrange(n, ^(){});
   buf[0] = get_kernel_sub_group_count_for_ndrange(0, ^(){}); // expected-error{{illegal call to 'get_kernel_sub_group_count_for_ndrange', expected 'ndrange_t' argument type}}
   buf[0] = get_kernel_sub_group_count_for_ndrange(n, 1); // expected-error{{illegal call to 'get_kernel_sub_group_count_for_ndrange', expected block argument type}}
 }
 
 #pragma OPENCL EXTENSION cl_khr_subgroups : disable
 
-kernel void foo1(global int *buf)
+kernel void foo1(global unsigned int *buf)
 {
   ndrange_t n;
   buf[0] = get_kernel_max_sub_group_size_for_ndrange(n, ^(){}); // expected-error {{use of declaration 'get_kernel_max_sub_group_size_for_ndrange' requires cl_khr_subgroups extension to be enabled}}
 }
 
-kernel void bar1(global int *buf)
+kernel void bar1(global unsigned int *buf)
 {
   ndrange_t n;
   buf[0] = get_kernel_sub_group_count_for_ndrange(n, ^(){}); // expected-error {{use of declaration 'get_kernel_sub_group_count_for_ndrange' requires cl_khr_subgroups extension to be enabled}}
 }