[Bug target/115054] __float128 and _Float16 use incorrect ABI on x86-64 MinGW

[tmgross at umich dot edu via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054

--- Comment #9 from Trevor Gross <tmgross at umich dot edu> ---
Candidate patch for the f16 part
https://gcc.gnu.org/pipermail/gcc-patches/2025-August/693822.html