[esnext] Update String.p.matchAll as per spec changes

As per (https://github.com/tc39/proposal-string-matchall/pull/41), String.p.matchAll's fallback was removed.
Additionally, removed a IsNullOrUndefined check that was already covered by MaybeCallFunctionAtSymbol.
Updates to Test262 has been submitted: https://github.com/tc39/test262/pull/1990

Bug: v8:6890
Change-Id: I246cbbcb4641ebded704c5f772809f182deaa30e
Reviewed-on: https://chromium-review.googlesource.com/c/1369091
Commit-Queue: Peter Wong <peter.wm.wong@gmail.com>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58172}

src/builtins/builtins-string-gen.cc

@@ -1521,57 +1521,41 @@ TF_BUILTIN(StringPrototypeMatchAll, StringBuiltinsAssembler) {
   RequireObjectCoercible(context, receiver, method_name);
 
   // 2. If regexp is neither undefined nor null, then
-  Label tostring_and_create_regexp_string_iterator(this, Label::kDeferred);
-  TVARIABLE(String, var_receiver_string);
-  GotoIf(IsNullOrUndefined(maybe_regexp),
-         &tostring_and_create_regexp_string_iterator);
-  {
-    // a. Let matcher be ? GetMethod(regexp, @@matchAll).
-    // b. If matcher is not undefined, then
-    //   i. Return ? Call(matcher, regexp, « O »).
-    auto if_regexp_call = [&] {
-      // MaybeCallFunctionAtSymbol guarantees fast path is chosen only if
-      // maybe_regexp is a fast regexp and receiver is a string.
-      var_receiver_string = CAST(receiver);
-      CSA_ASSERT(this, IsString(var_receiver_string.value()));
-
-      RegExpMatchAllAssembler regexp_asm(state());
-      regexp_asm.Generate(context, native_context, maybe_regexp,
-                          var_receiver_string.value());
-    };
-    auto if_generic_call = [=](Node* fn) {
-      Callable call_callable = CodeFactory::Call(isolate());
-      Return(CallJS(call_callable, context, fn, maybe_regexp, receiver));
-    };
-    MaybeCallFunctionAtSymbol(
-        context, maybe_regexp, receiver,
-        isolate()->factory()->match_all_symbol(),
-        DescriptorIndexAndName{JSRegExp::kSymbolMatchAllFunctionDescriptorIndex,
-                               RootIndex::kmatch_all_symbol},
-        if_regexp_call, if_generic_call);
-    Goto(&tostring_and_create_regexp_string_iterator);
-  }
-  BIND(&tostring_and_create_regexp_string_iterator);
-  {
+  //   a. Let matcher be ? GetMethod(regexp, @@matchAll).
+  //   b. If matcher is not undefined, then
+  //     i. Return ? Call(matcher, regexp, « O »).
+  auto if_regexp_call = [&] {
+    // MaybeCallFunctionAtSymbol guarantees fast path is chosen only if
+    // maybe_regexp is a fast regexp and receiver is a string.
+    TNode<String> s = CAST(receiver);
+
     RegExpMatchAllAssembler regexp_asm(state());
+    regexp_asm.Generate(context, native_context, maybe_regexp, s);
+  };
+  auto if_generic_call = [=](Node* fn) {
+    Callable call_callable = CodeFactory::Call(isolate());
+    Return(CallJS(call_callable, context, fn, maybe_regexp, receiver));
+  };
+  MaybeCallFunctionAtSymbol(
+      context, maybe_regexp, receiver, isolate()->factory()->match_all_symbol(),
+      DescriptorIndexAndName{JSRegExp::kSymbolMatchAllFunctionDescriptorIndex,
+                             RootIndex::kmatch_all_symbol},
+      if_regexp_call, if_generic_call);
 
-    // 3. Let S be ? ToString(O).
-    var_receiver_string = ToString_Inline(context, receiver);
-
-    // 4. Let matcher be ? RegExpCreate(R, "g").
-    TNode<Object> regexp = regexp_asm.RegExpCreate(
-        context, native_context, maybe_regexp, StringConstant("g"));
-
-    // 5. Let global be true.
-    // 6. Let fullUnicode be false.
-    // 7. Return ! CreateRegExpStringIterator(matcher, S, global, fullUnicode).
-    TNode<Int32T> global = Int32Constant(1);
-    TNode<Int32T> full_unicode = Int32Constant(0);
-    TNode<Object> iterator = regexp_asm.CreateRegExpStringIterator(
-        native_context, regexp, var_receiver_string.value(), global,
-        full_unicode);
-    Return(iterator);
-  }
+  RegExpMatchAllAssembler regexp_asm(state());
+
+  // 3. Let S be ? ToString(O).
+  TNode<String> s = ToString_Inline(context, receiver);
+
+  // 4. Let rx be ? RegExpCreate(R, "g").
+  TNode<Object> rx = regexp_asm.RegExpCreate(context, native_context,
+                                             maybe_regexp, StringConstant("g"));
+
+  // 5. Return ? Invoke(rx, @@matchAll, « S »).
+  Callable callable = CodeFactory::Call(isolate());
+  TNode<Object> match_all_func =
+      GetProperty(context, rx, isolate()->factory()->match_all_symbol());
+  Return(CallJS(callable, context, match_all_func, rx, s));
 }
 
 class StringPadAssembler : public StringBuiltinsAssembler {

test/mjsunit/harmony/string-matchAll-deleted-matchAll.js

+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-string-matchall
+
+delete RegExp.prototype[Symbol.matchAll];
+const str = 'a';
+assertThrows(() => str.matchAll(/\w/g), TypeError);

test/test262/test262.status

@@ -734,6 +734,10 @@
   'harness/detachArrayBuffer': [SKIP],
   'harness/detachArrayBuffer-host-detachArrayBuffer': [SKIP],
 
+  # Test needs to be updated to spec changes.
+  # https://github.com/tc39/test262/pull/1990
+  'built-ins/String/prototype/matchAll/regexp-prototype-has-no-matchAll': [FAIL],
+
   ############################ SKIPPED TESTS #############################
 
   # These tests take a looong time to run.