cc/gcc: fix C++ headers location

In case we build the C++ compiler, we have to tell gcc where to put the C++
headers, or else it will try to # put it in prefix/tuple/include, which we
make a symlink to sysroot/usr/include during the build, and that we delete
(the symlink!) after the build, but gcc will not look in sysroot/usr/inlcude
for C++ headers by default.

Implements a fix suggested by: Bryan Hundven <bryanhundven@gmail.com>

Reported-by: Anthony Foiani <anthony.foiani@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from a0924619112015bdaa81a0a2313d21ef38607bc2)

diff -durN gcc-4.4.0.orig/libgomp/configure gcc-4.4.0/libgomp/configure

--- gcc-4.4.0.orig/libgomp/configure	2009-04-21 11:08:08.000000000 +0200

+++ gcc-4.4.0/libgomp/configure	2009-05-27 21:38:19.000000000 +0200

@@ -3334,7 +3334,7 @@

 # Add -Wall -Werror if we are using GCC.

 if test "x$GCC" = "xyes"; then

-  XCFLAGS="$XCFLAGS -Wall -Werror"

+  XCFLAGS="$XCFLAGS -Wall"

 fi

 # Find other programs we need.