Include anonymous enum in ABI dumps

The definitions of anonymous enums are stored in "enum_types" entry in
lsdump files. The linker_set_key for an anonymous enum consists of the
enclosing scopes and the lexicographically smallest field.

Bug: 141709599
Test: ./test.py
Change-Id: I4cecfd593e29c5432af6847de2429350a4178842
13 files changed