[parser] Skipping inner funcs: fix sloppy block generators.

PreParser and Parser didn't agree whether a generator in a sloppy block is a
sloppy block function or not, and thus the data generated by PreParser was
inconsistent with what the Parser wanted to restore.

BUG=v8:5516, chromium:760116

Change-Id: I0fd3c267691b8afd63a1336774769caf551c143e
Reviewed-on: https://chromium-review.googlesource.com/642886Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47727}

src/parsing/parser.h

@@ -297,6 +297,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
       SET_ALLOW(harmony_dynamic_import);
       SET_ALLOW(harmony_async_iteration);
       SET_ALLOW(harmony_template_escapes);
+      SET_ALLOW(harmony_restrictive_generators);
 #undef SET_ALLOW
     }
     return reusable_preparser_;

test/cctest/parsing/test-preparser.cc

@@ -182,6 +182,14 @@ TEST(PreParserScopeAnalysis) {
       {"let var1 = function() { let var2; }"},
       {"const var1 = function() { let var2; }"},
 
+      {"function *f1() { let var2; }"},
+      {"let var1 = function *f1() { let var2; }"},
+      {"let var1 = function*() { let var2; }"},
+
+      {"async function f1() { let var2; }"},
+      {"let var1 = async function f1() { let var2; }"},
+      {"let var1 = async function() { let var2; }"},
+
       // Redeclarations.
       {"var var1; var var1;"},
       {"var var1; var var1; var1 = 5;"},
@@ -451,6 +459,9 @@ TEST(PreParserScopeAnalysis) {
 
       {"if (true) { function f1() {} function f2() { f1(); } }"},
 
+      {"if (true) { function *f1() {} }"},
+      {"if (true) { async function f1() {} }"},
+
       // Simple parameters.
       {"var1", ""},
       {"var1", "var1;"},

test/mjsunit/skipping-inner-functions.js

@@ -295,3 +295,22 @@ function TestSkippableFunctionInForOfHeaderAndBody() {
 }
 
 TestSkippableFunctionInForOfHeaderAndBody();
+
+(function TestSkippableGeneratorInSloppyBlock() {
+  var result = 0;
+
+  function lazy(ctxt_alloc_param) {
+    var ctxt_alloc_var = 10;
+    {
+      function *skip_me() {
+        result = ctxt_alloc_param + ctxt_alloc_var;
+        yield 3;
+      }
+      return skip_me;
+    }
+  }
+  // Test that parameters and variables of the outer function get context
+  // allocated even if we skip the inner function.
+  assertEquals(3, lazy(9)().next().value);
+  assertEquals(19, result);
+})();