Add boostrap lib to build multilib x86 GCC with OpenMP support

Build instructions:

  cd AOSP=<your-AOSP-path>
  cd $AOSP/bionic/libc
  ln -s arch-x86 arch-x86_64

  export NDK=$AOSP/ndk
  cd $NDK
  ./build/tools/gen-platforms.sh --dst-dir=$NDK --ndk-dir=$NDK --overlay --arch=x86_64

  # copy $NDK/platforms/android-9/arch-x86_64/usr/lib, lib64, and libx32 over

Change-Id: I021a34fa139456540bc0afdb1d9636df165f92fe
12 files changed