[PATCH 37/79] [NFC] Use typed pointers for null function pointers debug info (#1969)

[PATCH 37/79] [NFC] Use typed pointers for null function pointers debug info (#1969)

`PointerType::get(Context` will return typeless/opaque pointer. While it
is OK for KHR translator since it's being built on top of LLVM trunk,
where opaque pointers are enabled by default - it won't work for
intel/llvm, where their generation is disabled.

Upstream of https://github.com/intel/llvm/pull/9118

Signed-off-by: Sidorov, Dmitry <dmitry.sidorov@intel.com>
Gbp-Pq: Name 0037-NFC-Use-typed-pointers-for-null-function-pointers-de.patch