[Timers] Fix printing some `-ftime-report` sections twice. Fixes PR40328.

[vsapsai]

Summary

Starting from r324788 timer groups aren't cleared automatically when
printed out. As a result some timer groups were printed one more time.
For example, "Pass execution timing report" was printed again in
ManagedStatic<PassTimingInfo> destructor, "DWARF Emission" in
ManagedStatic<Name2PairMap> NamedGroupedTimers destructor.

Fix by clearing timer groups manually.

[thegameg]

LGTM, thanks!

[vsapsai]

Thanks for the fast review.

clang/tools/driver/cc1_main.cpp

#endif
   {
     llvm::TimeTraceScope TimeScope("ExecuteCompiler", StringRef(""));
     Success = ExecuteCompilerInvocation(Clang.get());
   }
 
   // If any timers were active but haven't been destroyed yet, print their
   // results now.  This happens in -disable-free mode.
   llvm::TimerGroup::printAll(llvm::errs());
+  llvm::TimerGroup::clearAll();
 
   if (llvm::timeTraceProfilerEnabled()) {
     SmallString<128> Path(Clang->getFrontendOpts().OutputFile);
     llvm::sys::path::replace_extension(Path, "json");
     auto profilerOutput =
         Clang->createOutputFile(Path.str(),
                                 /*Binary=*/false,
                                 /*RemoveFileOnSignal=*/false, "",

clang/tools/driver/cc1as_main.cpp

int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
   }
 
   // Execute the invocation, unless there were parsing errors.
   bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
 
   // If any timers were active but haven't been destroyed yet, print their
   // results now.
   TimerGroup::printAll(errs());
+  TimerGroup::clearAll();
 
   return !!Failed;
 }

clang/tools/driver/driver.cpp

#endif
     }
   }
 
   Diags.getClient()->finish();
 
   // If any timers were active but haven't been destroyed yet, print their
   // results now.  This happens in -disable-free mode.
   llvm::TimerGroup::printAll(llvm::errs());
+  llvm::TimerGroup::clearAll();
 
 #ifdef _WIN32
   // Exit status should not be negative on Win32, unless abnormal termination.
   // Once abnormal termiation was caught, negative status should not be
   // propagated.
   if (Res < 0)
     Res = 1;
 #endif
 
   // If we have multiple failing commands, we return the result of the first
   // failing command.
   return Res;
 }