simpleperf: add --generate-test-file option in debug-unwind cmd.

Recording files are usually too large to be used as test files.
So add this option to generate a small test file, which only contains
necessary info for unwinding a sample.

Bug: 181075274
Test: run simpleperf_unit_test
Change-Id: I1d04eac359453bdaee5fe861f97af1569ba4e7c1
3 files changed