Fix PR3988: extern inline functions get strong symbol definitions in
C99 mode.  This is a regression from an earlier patch of mine.

This also simplifies the linkage enums a bit.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69069 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed