[parser] Skipping inner funcs: Turn flag back on.

After closer investigation, the crashes / regressions we currently have are not
so bad that we couldn't have the flag on.

BUG=v8:5516

Change-Id: I1b70cf99de1707d659b2e0abcd3678ec71a530bf
Reviewed-on: https://chromium-review.googlesource.com/699997Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48276}

src/flag-definitions.h

@@ -878,7 +878,7 @@ DEFINE_BOOL(lazy_inner_functions, true, "enable lazy parsing inner functions")
 DEFINE_BOOL(aggressive_lazy_inner_functions, false,
             "even lazier inner function parsing")
 DEFINE_IMPLICATION(aggressive_lazy_inner_functions, lazy_inner_functions)
-DEFINE_BOOL(preparser_scope_analysis, false,
+DEFINE_BOOL(preparser_scope_analysis, true,
             "perform scope analysis for preparsed inner functions")
 DEFINE_IMPLICATION(preparser_scope_analysis, aggressive_lazy_inner_functions)