Turn on --ignition-generators by default.

This CL merely sets the --ignition-generators flag to true. This flag is
currently only meaningful in combination with --ignition.

BUG=

Review-Url: https://codereview.chromium.org/2065963002
Cr-Commit-Position: refs/heads/master@{#37144}

src/flag-definitions.h

@@ -303,7 +303,7 @@ DEFINE_BOOL(string_slices, true, "use string slices")
 // Flags for Ignition.
 DEFINE_BOOL(ignition, false, "use ignition interpreter")
 DEFINE_BOOL(ignition_eager, false, "eagerly compile and parse with ignition")
-DEFINE_BOOL(ignition_generators, false,
+DEFINE_BOOL(ignition_generators, true,
             "enable experimental ignition support for generators")
 DEFINE_STRING(ignition_filter, "*", "filter for ignition interpreter")
 DEFINE_BOOL(ignition_peephole, true, "use ignition peephole optimizer")