Add mclinker support: -fuse-ld=mcld

See http://code.google.com/p/mclinker/
    6502f082fed932c0609b475d5d6917103700e5a8

Change-Id: I3c782584f43a8216d868e016d5f416a574402702
Fix MIPS GCC to emit -m elf32ltsmip for linker

ARM/X86 GCC in NDK explicitly emit -m armelf_linux_eabi and -m elf_i386,
respectively, for linker.  Fix MIPS to do the same, to help mclinker
which is built vanilla and relies on either filename (eg.
eg. arm-linux-androideabi-ld.mcd implies arm) or -mtriple/-march/-m
to figure out the target

See 125708b8e3afa6007ce3aa7132165d27b719ccc3

Change-Id: I79d67b5a69884713b9a3aaa59012c9170b823068
Fixed GCC 4.8 ICE gen_thumb_movhi_clobber at config/arm/arm.md:5832

See issue https://code.google.com/p/android/issues/detail?id=52732,
and fix http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00732.html

Also see 78a68e851a2f6f9d00367cd38eeedf670bb80f01

Change-Id: Iad4deda17414f3165714da0b60f9f8cb2a6ef052
Use default visibility for the __cxa functions in eh_arm.cc.

Change-Id: I6f4b9adba43aa366c5107c8644a7a2afc840d193
OpenMP: Better CPU count detection for Linux

See b3cd55a4e23e443cc4561424e22c27fe7f05b5c1

Change-Id: Iafdee05e23c639fcd011550b38b2570670706c65