[Firm] support cygwin?

[KIMURA Masaru]

Hi,

just clone cparser from git and build it on cygwin.
but it looks unusable ATM.

$ ./build/debug/cparser.exe -o hello hello.c
error: unknown operating system 'win32' in target-triple

$ grep -e 'unknown operating system' $(find . -name '*.c')
./src/driver/target.c:          errorf(NULL, "unknown operating system
'%s' in target-triple", os);

but it looks having mingw support.
where can i start to fix this?

Peace,

P.S.
just make cparser vomits ton of -fPIC warning on cygwin.
and it looks simply uncool.