[Bug middle-end/108300] `abort()` macro cause bootstrap failure on *-w64-mingw32

[arsen at aarsen dot me via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108300

--- Comment #9 from Arsen Arsenović <arsen at aarsen dot me> ---
(In reply to LIU Hao from comment #8)
> The commit above just lets GCC bootstrap on Windows. The cause of this issue
> is still there.
> 
> Maybe it's possible to replace all direct calls to `abort()` in gcc and
> libcpp with `fancy_abort (__FILE__, __LINE__, __FUNCTION__)`, and eventually
> get rid of that macro.

See Jonathans comment above.  I'll do that refactor this week, likely.