The inclusion of mingw-w64-gcc fixes T5979.
This package contains gcc, g++, libraries, binaries, headers and
more software for building programs and projects targeting
MinGW-w64, 32 and 64 bits are supported but not multilib. The
MinGW-w64 Headers are added temporally here. Depends on
mingw-w64-binutils. Needs to be rebuilt again with modifications
in package.yml after rebuilding mingw-w64.
The build order is the following:
binutils -> headers -> bootstrap -> crt -> winpthreads -> gcc
Signed-off-by: Martin Reboredo <firstname.lastname@example.org>