New x86 toolchain: i686-linux-android-4.7

Build instructions:

export NDK=your-AOSP-path/ndk
cd $NDK ; ./build/tools/dev-cleanup.sh
./build/tools/download-toolchain-sources.sh /tmp/ndk-$USER/src
./build/tools/gen-platforms.sh --minimal --dst-dir=$NDK --ndk-dir=$NDK --arch=x86
./build/tools/build-gcc.sh /tmp/ndk-$USER/src $NDK --gdb-version=7.3.x x86-4.7 --try-64
rm -rf $NDK/toolchains/x86-4.7/prebuilt/linux-x86_64/sysroot
cp -a $NDK/toolchains/x86-4.7/prebuilt/linux-x86_64/* \
  $NDK/../prebuilts/gcc/linux-x86_64/x86/i686-linux-android-4.7

Change-Id: I7761d2c87f60ad5f7e00a26421020d3f42b35ecc
191 files changed