When we know that a dynamic_cast always returns null, we can make
CodeGenFunction::EmitDynamicCast always return null or throw a bad_cast 
exception.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129264 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed