MFC r258350:

MFC r258350:

Pull in r191896 from upstream llvm trunk:

  CaptureTracking: Plug a loophole in the "too many uses" heuristic.

  The heuristic was added to avoid spending too much compile time in a
  specially crafted test case (PR17461, PR16474) with many uses on a
  select or bitcast instruction can still trigger the slow case. Add a
  check for that case.

  This only affects compile time, don't have a good way to test it.

This fixes the excessive compile time spent on a specific file of the
graphics/rawtherapee port.

Reported by:	mandree
Approved by:	re (gjb)

git-svn-id: svn://svn.freebsd.org/base/stable/10@258607 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f