[api] Fix harmony formatting for CompileFunctionInContext

Add newline at the start of the function body.

BUG=v8:6190, v8:4958
R=littledan@chromium.org, adamk@chromium.org, caitp@igalia.com

Change-Id: I10db088ac9807a503382fd5080ad955e418d8b45
Reviewed-on: https://chromium-review.googlesource.com/466566Reviewed-by: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Josh Wolfe <jwolfe@igalia.com>
Cr-Commit-Position: refs/heads/master@{#44352}

src/api.cc

@@ -2298,7 +2298,7 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
     if (i::FLAG_harmony_function_tostring) {
       // Append linefeed and signal that text beyond the linefeed is not part of
       // the formal parameters.
-      brackets = factory->NewStringFromStaticChars("\n) {");
+      brackets = factory->NewStringFromStaticChars("\n) {\n");
       parameters_end_pos = source_string->length() + 1;
     } else {
       brackets = factory->NewStringFromStaticChars("){");
@@ -2309,8 +2309,8 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
   } else {
     if (i::FLAG_harmony_function_tostring) {
       source_string =
-          factory->NewStringFromStaticChars("(function anonymous(\n) {");
-      parameters_end_pos = source_string->length() - 3;
+          factory->NewStringFromStaticChars("(function anonymous(\n) {\n");
+      parameters_end_pos = source_string->length() - 4;
     } else {
       source_string = factory->NewStringFromStaticChars("(function(){");
     }

test/cctest/test-compiler.cc

@@ -605,7 +605,8 @@ TEST(CompileFunctionInContextHarmonyFunctionToString) {
           fun->ToString(env.local()).ToLocalChecked();
       v8::Local<v8::String> expected = v8_str(
           "function anonymous(event\n"
-          ") {return event\n"
+          ") {\n"
+          "return event\n"
           "}");
       CHECK(expected->Equals(env.local(), result).FromJust());
     }
@@ -630,7 +631,8 @@ TEST(CompileFunctionInContextHarmonyFunctionToString) {
           fun->ToString(env.local()).ToLocalChecked();
       v8::Local<v8::String> expected = v8_str(
           "function anonymous(\n"
-          ") {return 0\n"
+          ") {\n"
+          "return 0\n"
           "}");
       CHECK(expected->Equals(env.local(), result).FromJust());
     }