Recommit r148056 with fixes to deal with weirdness with bitfields in unions.

Original message: Make sure adding a field to a struct never reduces its size.  PR11745.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148070 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed