[SPIR-V][OpenCL] Type mismatch on OpStore instruction

The following snippet:
```c
kernel void k(global ulong *dst) {
  dst[0] = 123;
  dst[1] = 321;
  dst[2] = 1111;
}
```
Fails to validate:
```
$ clang -target spirv64v1.2 -O0 -fintegrated-objemitter store-issue.cl -c -o - | spirv-val -
error: line 31: OpStore Pointer <id> '17[%dst_addr]'s type does not match Object <id> '15[%dst]'s type.
  OpStore %dst_addr %dst Aligned 8

```