Add the "no-split-stack" attribute

This disable emission of segmented-stack prologues on a per-function basis, even
if segmented stacks are turned on globally.
Implement the fixed stack segment attribute
Add command line argument for setting fixedstacksegment size
Splitstack implementation for android
Splitstack support for arm/linux.
Add MIPS segmented stacks
Work around an assertion that rust is tripping