[PATCH] ARM: enable long calls for WoA

[Saleem Abdulrasool]

As Jim mentioned at the beginning, that there is some overhead to this, and enabling this unconditionally seems a bit heavy handed.  By improving the driver to be a bit more similar to gcc (adding support for -mlong-calls/-mno-long-calls), we can enable this as and when it is needed as the linker should indicate that the jump target is out of range.

http://reviews.llvm.org/D3247