[interpreter][stubs] Fixing issues found by machine graph verifier.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index ca2a97bd2c15e9ce47882e5db0a6cf51bff136b9..54bc699524c0b2883fc997d6fe76f79f4e47fc5a 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -442,6 +442,7 @@ DEFINE_BOOL(turbo_verify, DEBUG_BOOL, "verify TurboFan graphs at each phase")
 DEFINE_STRING(turbo_verify_machine_graph, nullptr,
               "verify TurboFan machine graph before instruction selection")
 DEFINE_BOOL(csa_verify, false, "verify TurboFan machine graph of code stubs")
+DEFINE_BOOL(trace_csa_verify, false, "trace code stubs verification")
 DEFINE_BOOL(turbo_stats, false, "print TurboFan statistics")
 DEFINE_BOOL(turbo_stats_nvp, false,
             "print TurboFan statistics in machine-readable format")