simpleperf: improve debug-unwind cmd.

In debug-unwind cmd:
1. Add --symfs option.
2. Add meta_info section when there isn't one.
3. Add file section when there isn't one.

Rename unwinding_result_reporter.py to debug_unwind_reporter.py,
and fix a small error in it.

Bug: http://b/72556486
Test: run simpleperf_unit_test.
Test: run debug_unwind_reporter.py manually.

Change-Id: Ibc66b7bfdc91a17f6f1c2c0e84f4769d2bcaa1e7
3 files changed