Use TARGET_OS_OSX macro for getting MAP_JIT flag dynamically.
Several fixes.
Use TARGET_OS_MAC macro in the executable allocator.
Fix MAP_JIT issues on Mac. Patch by Carlo Arenas.
Improve MAP_JIT falg usage on MacOS. Patch by Rich Siegel.
Executable allocator support added for newer Apply systems.
Typo fixes by Jason Hood.
Add test for fast-return + flag preservation. Patch by James Cowgill.