Bump sys-devel/binutils-linaro-2.24.0_p201406 -> sys-devel/binutils-linaro-2.24.0_p201408
Bump sys-devel/gcc-linaro-4.9_p201406 -> sys-devel/gcc-linaro-4.9_p201408
Add sys-devel/gcc-linaro-4.6_p201305 sys-devel/gcc-linaro-4.7_p201401 sys-devel/gcc-linaro-4.8_p201404
Bump sys-devel/gdb-linaro-7.7.1_p201406 -> sys-devel/gdb-linaro-7.8_p201408