OpaquePtr: use byval accessor instead of inspecting pointer type. NFC.
OpaquePtr: use byval accessor instead of inspecting pointer type. NFC.

The accessor can deal with both "byval(ty)" and "ty* byval" forms
seamlessly.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@365769 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm