The bash script that does the build will not even run due an error with
an extra "&& )" into the install2 option. There is also a problem with a
libstdc++ Makefile that might be caused by an error in bash, itself.
This sounds like an error in your configure arguments getting transcribed
into the generated makefiles to me. It's not an extra '&& )', it's something
missing between the '&&' and the ')' that's the real problem, and that
probably happened because a shell variable used to generate the output from
that stage of configure ended up being empty because of a failure of a
pattern-match earlier on because of a mis-spelt option. (Well, for example.)
Configure scripts aren't terribly robust against syntax issues and
metacharacters, let's just hope nobody ever invents a target triplet with
backtick-rm-dash-rf-star-backtick in it![*]
I do not have a clue whether a particular patch
should be reversed or not before being applied, in ada, for example. I
just accepted the default and hoped for the best.
You probably shouldn't be patching anything at all. Gcc should build for
cygwin OOTB; there are cygwin-specific patches that add things like
-mno-cygwin, but the basic compiler should be fine as it stands.