[Bug libgcc/100341] build fails of error: '__LIBGCC_DF_EPSILON__' undeclared (first use in this function) for mingw-w64

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100341

--- Comment #1 from cqwrteur <unlvsur at live dot com> ---
it looks we need to rebuild cross compiler before Canadian cross-compile
because the cross compiler itself might not provide the macros we need.