[runtime] Kill the %NumberToIntegerMapMinusZero runtime entry.

src/s390/code-stubs-s390.cc

Index: src/s390/code-stubs-s390.cc
diff --git a/src/s390/code-stubs-s390.cc b/src/s390/code-stubs-s390.cc
index f2a451669163bd50c1375ea292c640a77eca14d9..38da61319f2dfdae864fbce8c5760b27723a24ba 100644
--- a/src/s390/code-stubs-s390.cc
+++ b/src/s390/code-stubs-s390.cc
@@ -1391,7 +1391,6 @@ void LoadIndexedStringStub::Generate(MacroAssembler* masm) {
                                           &miss,  // When not a string.
                                           &miss,  // When not a number.
                                           &miss,  // When index out of range.
-                                          STRING_INDEX_IS_ARRAY_INDEX,
                                           RECEIVER_IS_STRING);
   char_at_generator.GenerateFast(masm);
   __ Ret();
@@ -2223,13 +2222,7 @@ void StringCharCodeAtGenerator::GenerateSlow(
     // index_ is consumed by runtime conversion function.
     __ Push(object_, index_);
   }
-  if (index_flags_ == STRING_INDEX_IS_NUMBER) {
-    __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero);
-  } else {
-    DCHECK(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
-    // NumberToSmi discards numbers that are not exact integers.
-    __ CallRuntime(Runtime::kNumberToSmi);
-  }
+  __ CallRuntime(Runtime::kNumberToSmi);
   // Save the conversion result before the pop instructions below
   // have a chance to overwrite it.
   __ Move(index_, r2);
@@ -2560,7 +2553,7 @@ void SubStringStub::Generate(MacroAssembler* masm) {
   // r5: from index (untagged)
   __ SmiTag(r5, r5);
   StringCharAtGenerator generator(r2, r5, r4, r2, &runtime, &runtime, &runtime,
-                                  STRING_INDEX_IS_NUMBER, RECEIVER_IS_STRING);
+                                  RECEIVER_IS_STRING);
   generator.GenerateFast(masm);
   __ Drop(3);
   __ Ret();