The math library GMP 5.0.4 has a \377 and \376 error in the build. I did the .\configure
followed by the 'make', having trouble finding the root cause, output below:

Making all in mpn
make[2]: Entering directory `/home/boyerl/gcc-4.7.0/gmp/mpn'
/bin/sh ../libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -D__GMP_WITHIN_GMP -I.. -DOPERATION_`echo fib_table | sed 's/_$//'` -m32 -O2 -pedantic -fomit-frame-pointer -mtune=corei7 -march=corei7 -c -o fib_table.lo fib_table.c
libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -D__GMP_WITHIN_GMP -I.. -DOPERATION_fib_table -m32 -O2 -pedantic -fomit-frame-pointer -mtune=corei7 -march=corei7 -c fib_table.c -o fib_table.o
In file included from ../gmp-impl.h:102:0,
from fib_table.c:3:
../gmp-mparam.h:1:1: error: expected identifier or '(' before '!' token
../gmp-mparam.h:1:1: error: stray '\377' in program
../gmp-mparam.h:1:1: error: stray '\376' in program
../gmp-mparam.h:1:14: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:16: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:18: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:20: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:22: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:24: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:26: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:28: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:30: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:32: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:34: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:36: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:38: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:40: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:42: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:44: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:46: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:48: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:50: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:52: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:54: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:56: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:58: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:60: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:62: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:64: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:66: warning: null character(s) ignored [enabled by default]
../gmp-mparam.h:1:68: warning: null character(s) ignored [enabled by default]
In file included from ../gmp-impl.h:111:0,
from fib_table.c:3:
c:\mingw\bin\../lib/gcc/mingw32/4.6.2/../../../../include/inttypes.h:272:1: error: unknown type name 'wchar_t'
c:\mingw\bin\../lib/gcc/mingw32/4.6.2/../../../../include/inttypes.h:273:29: error: unknown type name 'wchar_t'
c:\mingw\bin\../lib/gcc/mingw32/4.6.2/../../../../include/inttypes.h:274:1: error: unknown type name 'wchar_t'
c:\mingw\bin\../lib/gcc/mingw32/4.6.2/../../../../include/inttypes.h:275:9: error: unknown type name 'wchar_t'
Makefile:417: recipe for target `fib_table.lo' failed

Thanks.

Installed gcc-core, gcc-g++ to cygwin, compiled OK.