Enable -fuse-init-array for Android X86/MIPS.

The dynamic linker of Android does not support .ctors/.dtors.
We should emit .init_array and .fini_array regardless the
gcc version.

NOTE: This patch does not affect the ARM backend, because
it is required to generate .init_array and .fini_array
for program targeting ARM AAPCS and AEABI.

llvm-svn: 168309