TypeFinder did not find types under DIArgList. This resulted in a case
of invalid IR after GlobalOpt removed a global that was the only
non-DIArgList use of a struct type.
error: use of undefined type named 'struct.S'
call void @llvm.dbg.value(
metadata !DIArgList([1 x %struct.S]* undef, i64 %idxprom),
metadata !24, metadata !DIExpression([...]))
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D103306
