[lldb][MachO] Fix section type recognition for new DWARF 5 sections

When LLDB needs to access a debug section, it generally calls
SectionList::FindSectionByType with the corresponding type (we have one type for
each DWARF section). However, the missing entries made some sections be
classified as "eSectionTypeOther", which makes all calls to `FindSectionByType`
fail.

With this patch, a check-lldb build with
`-DLLDB_TEST_USER_ARGS=--dwarf-version=5` reports a much lower number of
failures:

  Unsupported      :  327
  Passed           : 2423
  Expectedly Failed:   16
  Unresolved       :    2
  Failed           :   52

This is down from previously 400~ failures.

Differential Revision: https://reviews.llvm.org/D153433