* Rename MethodPass class to FunctionPass

  - Rename runOnMethod to runOnFunction
* Transform getAnalysisUsageInfo into getAnalysisUsage
  - Method is now const
  - It now takes one AnalysisUsage object to fill in instead of 3 vectors
    to fill in
  - Pass's now specify which other passes they _preserve_ not which ones
    they modify (be conservative!)
  - A pass can specify that it preserves all analyses (because it never
    modifies the underlying program)
* s/Method/Function/g in other random places as well

llvm-svn: 2333