[Bug libgcc/69233] fixtfti returns bad value for TI overflow

[munroesj at us dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69233

--- Comment #2 from Steven Munroe <munroesj at us dot ibm.com> ---
Well the language spec may not specify. But I can ask the platform to be
consistent with itself. For PowerISA I would expect long double -> __int128 to
be consistent with double -> long, which saturates (INT_MAX).

Also the current fixtfti implementation is very slow.

So while this may not be a general GCC (libgcc) bug. I don't think anyone would
mind if the PowerPC platform optimized this function and made its behavour
consistent with the PowerISA.