Implement new Function.prototype.toString and fix CreateDynamicFunction parsing

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 955e0832ed73317ff32242d9675d51416d5bc0ff..f7bdf6770f14ab816df8bdd0c190839393e674e5 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -2275,9 +2275,14 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
                         Function);
   TRACE_EVENT0("v8", "V8.ScriptCompiler");
   i::Handle<i::String> source_string;
+  int parameters_end_pos = i::kNoSourcePosition;
   auto factory = isolate->factory();
   if (arguments_count) {
-    source_string = factory->NewStringFromStaticChars("(function(");
+    if (i::FLAG_harmony_function_tostring) {
+      source_string = factory->NewStringFromStaticChars("(function anonymous(");
+    } else {
+      source_string = factory->NewStringFromStaticChars("(function(");
+    }
     for (size_t i = 0; i < arguments_count; ++i) {
       IsIdentifierHelper helper;
       if (!helper.Check(*Utils::OpenHandle(*arguments[i]))) {
@@ -2295,12 +2300,24 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
                                       ',')).ToHandle(&source_string);
       RETURN_ON_FAILED_EXECUTION(Function);
     }
-    auto brackets = factory->NewStringFromStaticChars("){");
+    i::Handle<i::String> brackets;
+    if (i::FLAG_harmony_function_tostring) {
+      brackets = factory->NewStringFromStaticChars("\n) {");
+      parameters_end_pos = source_string->length() - 3;
+    } else {
+      brackets = factory->NewStringFromStaticChars("){");
+    }
     has_pending_exception = !factory->NewConsString(source_string, brackets)
                                  .ToHandle(&source_string);
     RETURN_ON_FAILED_EXECUTION(Function);
   } else {
-    source_string = factory->NewStringFromStaticChars("(function(){");
+    if (i::FLAG_harmony_function_tostring) {
+      source_string =
+          factory->NewStringFromStaticChars("(function anonymous(\n) {");
+      parameters_end_pos = source_string->length() - 3;
+    } else {
+      source_string = factory->NewStringFromStaticChars("(function(){");
+    }
   }
 
   int scope_position = source_string->length();
@@ -2350,9 +2367,9 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
   has_pending_exception =
       !i::Compiler::GetFunctionFromEval(
            source_string, outer_info, context, i::SLOPPY,
-           i::ONLY_SINGLE_FUNCTION_LITERAL, eval_scope_position, eval_position,
-           line_offset, column_offset - scope_position, name_obj,
-           source->resource_options)
+           i::ONLY_SINGLE_FUNCTION_LITERAL, parameters_end_pos,
+           eval_scope_position, eval_position, line_offset,
+           column_offset - scope_position, name_obj, source->resource_options)
            .ToHandle(&fun);
   if (has_pending_exception) {
     isolate->ReportPendingMessages();