[OpenCL] Re-fix invalid address space generation for clk_event_t arguments of...

[OpenCL] Re-fix invalid address space generation for clk_event_t arguments of enqueue_kernel builtin function

Summary:
https://reviews.llvm.org/D53809 fixed wrong address space(assert in debug build)
generated for event_ret argument. But exactly the same problem exists for
event_wait_list argument. This patch should fix both.

Reviewers: Anastasia, yaxunl

Reviewed By:  Anastasia

Subscribers: kristina, ebevhan, cfe-commits

Differential Revision: https://reviews.llvm.org/D59985

llvm-svn: 358151