[lipo]: merge from trunk

[Xinliang David Li <davidxl@google.com>]

This is a merge from trunk 151395:151806

Along with the merge, several fixes to resolve the conflicts:

1) Disallow auxiliary functions in ipa early sra. The aux functions
   may get deleted.
2) Change the assembler name for sra transformed function to avoid
   name conflict in assembly file -- the conflict may come from a
   transformed function and another function in aux module which is
   emitted (e.g, in comdat)
3) Due to the phase ordering change of thunk emission, thunks for external
   auxilary functions are conditionally emitted -- leading to inconsistent
   comdat group (with the defining primary module) -- this can result in
   unsats.
4) during cfg fixup for sra transformation, the eh landing pad can be missing.
   This is due to the wrong order of eh edge manipulation.

Testing: SPEC2k int with LIPO -- all clean
             SPEC06 (C/C++) with LIPO -- all clean except deallI with
an outstanding problem: missing ipa summary for a new generated
function.


David