[GSoC] Port gcc - status after week 4

Hi,

Last week I started porting libgmp, libmpfr, and libmpc. Initially I
got stuck on the cross compilation issue and then referred to the
libgmp manual to solve it. All these libraries expect --host and
--build arguments in configure stage for cross compilation. I also
used --disable-shared and --disable-static flags in configure stage.

There were problems with locating the cross-compiler toolchain and and
flags were not being passed properly during the compilation test to
the gcc. I had to define the CFLAGS in the Makefile itself and pass
them to the configure script. But, this was quick and dirty way to
proceed, i will look for some other ways.
This is the flag that i had to pass:
DEP_CFLAGS = -I../../../../lib/posix -I../../../../lib/c/include
-imacros ../../../../../config.h -fexec-charset=UTF-8
-fwide-exec-charset=UTF-32LE -finput-charset=UTF-8 -ffreestanding
-fno-builtin -nostdlib -nostdinc -std=gnu99 -D__LE__ -march=pentium
-fno-omit-frame-pointer

Now, I tried cross-compiling libgmp, libmpfr and libmpc one by one.

Log for libgmp build shows that it could not find wchar.h and there ws
undefined reference to memcpy. Similarly, libmpfr could not find
memory.h, wchar.h, sys/fpu.h, fenv.h and gmp.h. There were undefined
references to fopen, ferror, fclose, memmove, memset, setlocale,
strtol, gettimeofday, round, trunc, floor, ceil and nearbyint. There
were undefined references to fopen, ferror and fclose in case of
libmpc. I will implement some of the missing functions in libposix.
Undefined references to memcpy, memmove, memset, fopen, fclose,