Rename lib64 to lib until both aarch64 and mips64el compiler are
built to look for sysroot/usr/lib64.
Change-Id: Ib9b40a432f7b27c25990e5bdba6ab11db6b2fb6a
Also
1) rename lib -> lib64
2) add src/ for android-20/arch-arm64 and arch-mips64
3) delete android-9/arch-arm64 and arch-mips64
Change-Id: I4958c4e52946e29e57b910f39ff0104200853a06