c-family: Support #pragma region/endregion [PR85487]
These pragmas are used by some editors to mark regions of code for
grouping and folding. GCC should silently ignore them, rather than
giving -Wunknown-pragmas warnings.
PR c/85487
gcc/ChangeLog:
* doc/cpp/pragmas.rst (Pragmas): Document region pragmas.
gcc/c-family/ChangeLog:
* c-pragma.cc (handle_pragma_ignore): New function.
(init_pragma): Register region and endregion pragmas.