Summary:
Add Max ModFlagBehavior, which can be used to take the max of two
module flag values when merging modules. Use it for the PIE and PIC
levels.
This avoids an error when we try to import from a module built -fpic
into a module built -fPIC, for example. For both PIE and PIC levels,
this will be legal, since the code generation gets more conservative
as the level is increased. Therefore we can take the max instead of
somehow trying to block importing between modules compiled with
different levels.
Reviewers: tmsriram, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33418
llvm-svn: 303590
2db1369c1f