bump binutils to 2.24 (prerequisite for microblaze)
bump gcc version to 4.8.2 (prerequisite for microblaze)

copied the 4.8.1 patch for 4.8.2.

Hunk 2/4 of gcc/config/rs6000/sysv4.h failed to apply;
that part adds the secure-plt functionality to LINK_TARGET_SPEC.
so the patch was adapted for the new macro definition in GCC and
*should* work, however it was not tested.
musl: add a patch for microblaze so gcc's and musl's definition matches

otherwise libstc++ will fail to build:
libstdc++-v3/include/bits/basic_string.h:3022:23: note: mismatched types
‘std::size_t {aka long unsigned int}’ and ‘size_t {aka unsigned int}’

it's questionable whether the patch belongs into musl or gcc (because all
other 32bit archs use int for size_t), but this works for the moment
and finding the hardcoded definition of __SIZE_TYPE__ for microblaze
in gcc's build system could become annoying.
add clean.sh to cleanup old builds
gcc 4.8.2 patch: add dynlinker name for musl microblaze