cross-compile/mingw: comment on sigrok specific "MXE fixes" patch
No change in behaviour, just comments and grouping and whitespace fixup.
Separate the binutils downgrade from the glib downgrade. Provide empty
lines for faster editor navigation. Provide comments for human readers.
Keep MXE's style of glib.mk indentation when disabling warnings.
This patch no longer applies to recent MXE versions, but might as well
have become obsolete. A build without these "MXE fixes" patches is
attempted, the result is yet to get determined. Needs more consideration.