[SubZero] Generate MIPS.abiflags section

The patch generates MIPS.abiflags section. This section contains a
versioned data structure with essential information required for
loader to determine the requirements of the application.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2471883005 .

Patch from Jaydeep Patil <jaydeep.patil@imgtec.com>.
8 files changed