Basic handling of CIE version 4 in dwarf reading

CIE looks like it's been emitted by clang since ~May 2015 [1]. This
means that we didn't have any CFI because this parse aborted, which
meant that all stack walks reverted to stack scanning. Allow expected
values for address size and segment descriptor size through so that
dump_syms can generate at least somewhat reasonable data.


Change-Id: I6dc92f51c4afd25c2adff92c09ccb8bb03bf9112
Reviewed-by: Mark Mentovai <>
Cr-Mirrored-Commit: bbebd8d5e7d61666c3a2dae82867bb7b5aeda639
5 files changed