[PATCH] [Reassocate] Add support for vector instructions.

[Sanjay Patel]

>>! In D5222#7, @mcrosier wrote:

> Good question.  When I added support for unsafe-math I checked the instruction FPMath flags directly and not the function attributes.  That doesn't mean it couldn't work that way, I just didn't implement it that way.  Does this effect anything other than simplifying lit test creation?  If this is commonly done, please file a PR and I'll be happy to address it.

Hi Chad,
I think that the function-level attribute needs to be handled too.
I've filed http://llvm.org/bugs/show_bug.cgi?id=21291 based on the discussion with Hal in http://reviews.llvm.org/D5787.

http://reviews.llvm.org/D5222