dsymutil: support dwarf version mismatches between object and clang module

This adds a missing call to maybeUpdateMaxDwarfVersion when visitng a
clang module. Failing to do so will cause a failure when emitting
DWARF 4 forms into a CU that AsmPrinter believes to be DWARF 2.

rdar://problem/33666528

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310392 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed