introduce a new TargetLibraryInfo pass, which transformations can use to
query about available library functions.  For now this just has
memset_pattern16, which exists on darwin, but it can be extended for a
bunch of other things in the future.

llvm-svn: 125965
GitOrigin-RevId: 0e125bb4d0f153ac18fc86adc1bedc33c6176f34
5 files changed