[PATCH] [mips64] Add support for MCJIT for MIPS64

[Vladimir Stefanovic]

This is the list of passing tests now:
    LLVM :: ExecutionEngine/MCJIT/cross-module-sm-pic-a.ll
    LLVM :: ExecutionEngine/MCJIT/eh-lg-pic.ll
    LLVM :: ExecutionEngine/MCJIT/eh-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/hello-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/multi-module-sm-pic-a.ll
    LLVM :: ExecutionEngine/MCJIT/non-extern-addend-smallcodemodel.ll
    LLVM :: ExecutionEngine/MCJIT/remote/cross-module-sm-pic-a.ll
    LLVM :: ExecutionEngine/MCJIT/remote/multi-module-sm-pic-a.ll
    LLVM :: ExecutionEngine/MCJIT/remote/test-global-init-nonzero-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/remote/test-ptr-reloc-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/stubs-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/test-global-init-nonzero-sm-pic.ll
    LLVM :: ExecutionEngine/MCJIT/test-ptr-reloc-sm-pic.ll

http://reviews.llvm.org/D5913