Win32 COFF Support - Patch 2

Here's the 2nd patch.

And a git patch is attached this time (Can't really make an svn style
patch until the 1st patch is committed).

- Michael Spencer

ms-coff-patch-2.patch (3.25 KB)

Looks good, committed in r108103. I changes various _OS arguments to be named OS. Please don't use underbars as the first character of an identifier, they are a reserved namespace for the compiler implementation (with capital letters).