When more than one Module is imported into the same context, such as during
an LTO build before linking the modules, ODR type uniquing may cause types
to point to a different CU. This check does not make sense in this case.
This fixes the error reported in PR34944.
https://bugs.llvm.org/show_bug.cgi?id=34944
rdar://problem/34940685
This reapplies a cleaner implementation of r316049.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316052 91177308-0d34-0410-b5e6-96231b3b80d8
