This commit backports a patch to the GCC 10.3.0 we build for Windows
cross-compilation in Guix. The commit has been backported to the GCC
releases/gcc-10 branch, but hasn't yet made it into a release.

The patch corrects a regression from an earlier GCC commit, see:
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=357c4350680bf29f0c7a115424e3da11c53b5582
and
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=074226d5aa86cd3de517014acfe34c7f69a2ccc7,
related to the way newer versions of mingw-w64 implement setjmp/longjmp.

Ultimately this was causing a crash for us when Windows users were
viewing the network traffic tab inside the GUI. After some period, long
enough that a buffer would need reallocating, a call into FreeTypes
gray_record_cell() would result in a call to ft_longjmp (longjmp), which
would then trigger a crash.

Fixes: bitcoin-core/gui#582.

See also:
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=e8d1ca7d2c344a411779892616c423e157f4aea8.
https://bugreports.qt.io/browse/QTBUG-93476.

Github-Pull: bitcoin#24842
Rebased-From: 457148a