[test] Return analysis exit code for no tests.

NOTRY=true

Bug: v8:6917
Change-Id: I5f1edec76f3e67909b7d910187ab2d0bc774d10b
Reviewed-on: https://chromium-review.googlesource.com/822490
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50032}

tools/testrunner/deopt_fuzzer.py

@@ -369,7 +369,7 @@ class DeoptFuzzer(base_runner.BaseTestRunner):
 
     if num_tests == 0:
       print "No tests to run."
-      return 0
+      return exit_code
 
     print(">>> Deopt fuzzing phase (%d test cases)" % num_tests)
     progress_indicator = progress.PROGRESS_INDICATORS[options.progress]()

tools/testrunner/gc_fuzzer.py

@@ -255,7 +255,7 @@ class GCFuzzer(base_runner.BaseTestRunner):
 
     if num_tests == 0:
       print "No tests to run."
-      return 0
+      return exit_code
 
     print(">>> Fuzzing phase (%d test cases)" % num_tests)
     progress_indicator = progress.PROGRESS_INDICATORS[options.progress]()