[runtime] Kill the %NumberToIntegerMapMinusZero runtime entry.

src/mips64/code-stubs-mips64.cc

Index: src/mips64/code-stubs-mips64.cc
diff --git a/src/mips64/code-stubs-mips64.cc b/src/mips64/code-stubs-mips64.cc
index 3eee703dd6d7511dea3d334b55ac4eca425a33ff..5f7173ff7b360f82077d6bf90bb0848a7a47b0d6 100644
--- a/src/mips64/code-stubs-mips64.cc
+++ b/src/mips64/code-stubs-mips64.cc
@@ -1424,7 +1424,6 @@ 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();
@@ -2290,13 +2289,7 @@ void StringCharCodeAtGenerator::GenerateSlow(
   } else {
     __ 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.
@@ -2633,7 +2626,7 @@ void SubStringStub::Generate(MacroAssembler* masm) {
   // a3: from index (untagged)
   __ SmiTag(a3);
   StringCharAtGenerator generator(v0, a3, a2, v0, &runtime, &runtime, &runtime,
-                                  STRING_INDEX_IS_NUMBER, RECEIVER_IS_STRING);
+                                  RECEIVER_IS_STRING);
   generator.GenerateFast(masm);
   __ DropAndRet(3);
   generator.SkipSlow(masm, &runtime);