RFE: Add C99 aliasing rules analysis

[llvmbot]

Bugzilla Link	3951
Version	unspecified
OS	MacOS X
Reporter	LLVM Bugzilla Contributor

Extended Description

GCC's analysis analysis has always been a bit poor. It would be nice to have a tool that did a much better job at reporting potential C99 aliasing rules gotchas.

For an example of a compiler that can do some fine-grained alias analysis, see Sun's C compiler @ http://docs.sun.com/app/docs/doc/819-5265/bjais?a=view

For a good overview and commentary on the rules, see http://www.coding-guidelines.com/cbook/cbook1_1.pdf starting at page 960.