[OpenCL] Add clang extension for function pointers.
The new clang internal extension '__cl_clang_function_pointers'
allows use of function pointers and other features that have
the same functionality:
- Use of member function pointers;
- Unrestricted use of references to functions;
- Virtual member functions.
This not a vendor extension and therefore it doesn't require any
special target support. Exposing this functionality fully
will require vendor or Khronos extension.
Tags: #clang
Differential Revision: https://reviews.llvm.org/D94021
GitOrigin-RevId: 4fde2b6a0c080cb2a598383b5850038d67ca6833
14 files changed
