Revert "[lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)"
This reverts commit 1b12766883006b8aa9d1ff744e57317647aa052a because of
breaking the mac test suite.
I'm not certain this is the cause because of a concurrent build breakage
which masked this problem, but the failure messages are related to
symbol lookup, which makes this very likely.