private_typeinfo: propagate static flags in vmi search_above_dst method

This adds the test which was mistakenly not committed in r332763.

Patch by Ryan Prichard

Propagate the found_our_static_ptr and found_any_static_type flags from
__vmi_class_type_info::search_above_dst to its caller.

Fixes PR33425 and PR33487

Reviewed as https://reviews.llvm.org/D36446

llvm-svn: 332764