[PATCH android/toolchain/build] Add --enable-graphite option to build script

GCC 4.5 and up supports graphite optimization, and cloog and ppl are required. This change attempts to support some combinations of ppl and cloog/cloog-ppl libraries. Since cloog and ppl are written in C++, it implies we might suffer from C++ ABI breakage problems when host environment changes, that is a well-known issue in GNU/Linux distributions. Thus, we have to drop runtime libstdc++ dependency by statically linking libstdc++.

Code Review: https://review.source.android.com//#change,22033

PS: The attachment contains the patch against HEAD in Linaro's android/toolchain/build.git, but please make yours comments via gerrit since this change is generic in upstream.