[tsan] Use MonotonicNanoTime instead of NanoTime

[kubamracek]

Summary

Looks like there's a few places in TSan where we should really be using MonotonicNanoTime to avoid jumps in wall time.

[kubamracek]

Ping.

[kubamracek]

Ping.

lib/tsan/rtl/tsan_rtl.cc

if (internal_strcmp(flags()->profile_memory, "stdout") == 0) {
         Printf("ThreadSanitizer: failed to open memory profile file '%s'\n",
             &filename[0]);
       } else {
         mprof_fd = fd;
       }
     }
   }
 
-  u64 last_flush = NanoTime();
+  u64 last_flush = MonotonicNanoTime();
   uptr last_rss = 0;
   for (int i = 0;
       atomic_load(&ctx->stop_background_thread, memory_order_relaxed) == 0;
       i++) {
     SleepForMillis(100);
-    u64 now = NanoTime();
+    u64 now = MonotonicNanoTime();
 
     // Flush memory if requested.
     if (flags()->flush_memory_ms > 0) {
       if (last_flush + flags()->flush_memory_ms * kMs2Ns < now) {
         VPrintf(1, "ThreadSanitizer: periodic memory flush\n");
         FlushShadowMemory();
-        last_flush = NanoTime();
+        last_flush = MonotonicNanoTime();
       }
     }
     // GetRSS can be expensive on huge programs, so don't do it every 100ms.
     if (flags()->memory_limit_mb > 0) {
       uptr rss = GetRSS();
       uptr limit = uptr(flags()->memory_limit_mb) << 20;
       VPrintf(1, "ThreadSanitizer: memory flush check"
                  " RSS=%llu LAST=%llu LIMIT=%llu\n",

lib/tsan/rtl/tsan_rtl_report.cc

if (flags()->suppress_equal_addresses) {
     RacyAddress ra0 = {addr_min, addr_max};
     ctx->racy_addresses.PushBack(ra0);
   }
 }
 
 bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
   if (!flags()->report_bugs || thr->suppress_reports)
     return false;
-  atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
+  atomic_store_relaxed(&ctx->last_symbolize_time_ns, MonotonicNanoTime());
   const ReportDesc *rep = srep.GetReport();
   CHECK_EQ(thr->current_report, nullptr);
   thr->current_report = rep;
   Suppression *supp = 0;
   uptr pc_or_addr = 0;
   for (uptr i = 0; pc_or_addr == 0 && i < rep->mops.Size(); i++)
     pc_or_addr = IsSuppressed(rep->typ, rep->mops[i]->stack, &supp);
   for (uptr i = 0; pc_or_addr == 0 && i < rep->stacks.Size(); i++)