[PATCH] MC: Add .section directive to COFF

[Nico Rieck]

  I've added http://llvm.org/docs/Extensions.html for a recent commit where something like that can go, but I'm not sure what you see as an extension here as it implements what GAS already does (just not completely). The only exception, and what I forgot to mention, is that the implemented logic prevents sections with IMAGE_SCN_CNT_INITIALIZED_DATA and IMAGE_SCN_CNT_UNINITIALIZED_DATA at the same time.

http://llvm-reviews.chandlerc.com/D666