Build a toolchain that supports all graphite optimizations

Headline:
Build a toolchain that supports all graphite optimizations

Acceptance:
Linaro Android can be built with the provided toolchain using compiler flags including -floop-interchange -fgraphite-identity -floop-strip-mine -floop-block -ftree-loop-distribution -ftree-loop-distribute-patterns

Current (and probably final) builds:
https://android-build.linaro.org/builds/~linaro-android/toolchain-4.6-2011.08/#build=6
https://android-build.linaro.org/builds/~linaro-android/toolchain-4.5-2011.08/#build=2

Work items:
Modify the toolchain build process to allow generating an arm-linux-androideabi toolchain instead of a generic arm-eabi toolchain (needed because -ftree-parallelize-loops needs to know how to do pthreads on the target system): DONE
Modify the toolchain build process to build a bootstrap compiler first, use it to build bionic, then build the real compiler (needed because -ftree-parallelize-loops needs OpenMP support, which in turn needs to build libgomp, which depends on knowing about the target libc): DONE
Check if this toolchain can compile Linaro Android; report any compiler bugs showing up to the toolchain WG: DONE
Run it through the build server: DONE
Make sure it can build bootable Linaro Android images: DONE
Merge it into official build: DONE