simpleperf: report unwinding failures.

1. When --log debug is used, store unwinding results in
   UnwindingResultRecords in perf.data.
2. Use unwinding_result_reporter.py to report unwinding results.

This is to help finding different unwinding failures.

Bug: http://b/69383534
Test: run simpleperf_unit_test.
Test: run unwinding_result_reporter.py manually.
Change-Id: I6d7f107e9758b1ec55ed35b49657bb41d47e2178
diff --git a/simpleperf/nonlinux_support/nonlinux_support.cpp b/simpleperf/nonlinux_support/nonlinux_support.cpp
index 648b63a..4a2e82c 100644
--- a/simpleperf/nonlinux_support/nonlinux_support.cpp
+++ b/simpleperf/nonlinux_support/nonlinux_support.cpp
@@ -17,13 +17,15 @@
 // Add fake functions to build successfully on darwin.
 #include <android-base/logging.h>
 
-#include "dwarf_unwind.h"
 #include "environment.h"
+#include "OfflineUnwinder.h"
 
-bool UnwindCallChain(int, const ThreadEntry&, const RegSet&, const char*, size_t, bool,
+namespace simpleperf {
+bool OfflineUnwinder::UnwindCallChain(int, const ThreadEntry&, const RegSet&, const char*, size_t,
                      std::vector<uint64_t>*, std::vector<uint64_t>*) {
   return false;
 }
+}  // namespace simpleperf
 
 bool GetKernelBuildId(BuildId*) {
   return false;