make-source.sh creates a tarball of MXE.cc and the sources files which are
required to build gcc C/C++ toolchains for
- i686-w64-mingw32.shared
- x86_64-w64-mingw32.shared

See make-source.sh for modifications which are applied to MXE.cc before
packaging.

To build gcc and its dependencies from the extracted tarball, run

  make gcc

This will use the sources which came with this package.

To build gdb, run

  make gdb

The sources of gdb and of its dependencies will be downloaded on first build.

