Added GCC prerequisites (gmp, mpc, mpfr, isl) to repo

Since I store GCC tarball anyway, let's add the prerequisites
too so altcross-2stage.sh does not need internet duing the build

altcross-2stage.sh

@@ -34,8 +34,20 @@ getversion() {
 	echo "$ver"
 }
 
+unpack_to() {
+	local tarball="$1"
+	local destdir="$2"
+	local name="${tarball##*/}"
+	name="${name%%-*}"
+	destdir="${destdir}/${name}"
+
+	mkdir -p "$destdir"
+	tar --strip-components=1 -x -a -f "$tarball" -C "$destdir"
+}
+
 GCC_VERSION=`getversion $GCC_SOURCE`
 GCC_MAJOR_VERSION="${GCC_VERSION%%.*}"
+GCC_PREREQS="gmp-6.2.1.tar.bz2 mpc-1.2.1.tar.gz mpfr-4.1.0.tar.bz2 isl-0.24.tar.bz2"
 
 INSTALLDIR="`pwd`/inst/altcross-gcc-${GCC_VERSION}"
 BOOTSTRAP_INSTALLDIR="`pwd`/stage1/altcross-gcc-${GCC_VERSION}"
@@ -52,11 +64,12 @@ tar -x -a --strip-components=1 -f "$GCC_SOURCE" -C gcc
 tar -x -a --strip-components=1 -f "$GLIBC_SOURCE" -C glibc
 
 cd "gcc"
-sed -i contrib/download_prerequisites -e '/base_url=/s/ftp/http/'
-./contrib/download_prerequisites
 for p in $GCC_PATCHES; do
 	patch -p1 -i $p
 done
+for tarball in $GCC_PREREQS; do
+	unpack_to "$MYDIR/$tarball" "."
+done
 
 mkdir -p -m755 "$INSTALLDIR/bin" "$BOOTSTRAP_INSTALLDIR/bin"
 save_PATH="$PATH"