Do not dump records not visible outside a translation unit.

Also use non-mangled name for C structs and enums as their unique id.

We do this as attempt to protect against bugs similar to those mentioned
in https://android-review.googlesource.com/c/platform/external/clang/+/599002
which might not have been discovered yet.

Bug: 71486971

Test: Build android source tree for aosp_arm64_ab with -no-filter on
      header-abi-dumper.

Test: tests/test.py

Change-Id: I3e25425d9f3015cd7dece3bd5a27f88e050c1acb