toolchain/gcc: forward port missing patches to gcc 4.8.0

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36544 3c298f89-4303-0410-b956-a3cf2f4a3e73
toolchain/gcc: add support for 4.8-linaro

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36545 3c298f89-4303-0410-b956-a3cf2f4a3e73