Do partial inlining in BU. This resolves more call sites. Also add options...

Do partial inlining in BU.  This resolves more call sites.  Also add options to merge in globals during recursion and to back annotate DSNodes when function pointers are resolved.  This makes PA work for a whole lot more things (unresolved call sites being what has been killing various DSA based passes)

llvm-svn: 28859