Simpleperf: support reading symbols from .gnu_debugdata.

As in https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html,
elf files can store mini debug information in .gnu_debugdata.

Bug: 27744639

Change-Id: If4a53a4a1332824388ee309ac63a008dc5cf8d5c
10 files changed