1. In /system/lib/libart.so, the ranges of functions covered by .eh_frame
and .ARM.exidx overlap with each other. Currently, we don't check .eh_frame
if the address is in the ranges of functions covered by .ARM.exidx. It leads
to a wrong unwinding result. So change the logic to first try .eh_frame and
.debug_frame, if it fails, then try .ARM.exidx.
2. Add test for Item 1.
Bug: http://b/35251937
Test: run backtrace_test.
Change-Id: Ic412705617c300bc69b4ece178cc2e1bb3eb765b
1. Read .ARM.exidx and .ARM.extab, provides these data to libunwind
through AccessMem.
2. In FindProcInfo, search .ARM.exidx for the idx entry of function
containing ip.
3. Add structures to store .ARM.exidx info in DebugFrameInfo, and
clean up the structure.
4. Add tests to test each unwind information (.eh_frame, .debug_frame,
.gnu_debugdata, .ARM.exidx) separately.
Bug: http://b/30974693
Test: run backtrace_test.
Test: run simpleperf runtest.py.
Change-Id: I9377a54379158bd35860efcf0e011423be7350d4
