cc/gcc: remove --enable-symver option

That option is coming from the original crosstool, and is not entirely
understand here.

Moreover, it breaks with newer gcc-s: 4.6.1 now breaks while configuring
libjava (and probably some other libs as well, untested).

There is an related bug report to the gcc BZ:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49555

If need be, the old behavior can be restored with:
CC_CORE_EXTRA_CONFIG_ARRAY="--enable-symver=gnu"
CC_EXTRA_CONFIG_ARRAY="--enable-symver=gnu"

Reported-by: Bryan Hundven <bryanhundven@gmail.com>
Reviewed-by: Bryan Hundven <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 http://sourceware.org/ml/binutils/2007-07/msg00401.html

 http://sourceware.org/bugzilla/show_bug.cgi?id=4970

 --- binutils/configure

 +++ binutils/configure

 @@ -5601,6 +5601,7 @@ case "${host}" in

    *-*-mingw* | *-*-cygwin ) RPATH_ENVVAR=PATH ;;

    *) RPATH_ENVVAR=LD_LIBRARY_PATH ;;

  esac

 +RPATH_ENVVAR="cant_touch_this_nah_nah_nah"

  # On systems where the dynamic library environment variable is PATH,

  if test "$RPATH_ENVVAR" = PATH; then