[turbofan] Do not lower (One|Two)ByteSeqString(Get|Set)Char intrinsics.

Review URL: https://codereview.chromium.org/1452113002

Cr-Commit-Position: refs/heads/master@{#32028}

src/compiler/js-intrinsic-lowering.cc

@@ -74,16 +74,8 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceMathFloor(node);
     case Runtime::kInlineMathSqrt:
       return ReduceMathSqrt(node);
-    case Runtime::kInlineOneByteSeqStringGetChar:
-      return ReduceSeqStringGetChar(node, String::ONE_BYTE_ENCODING);
-    case Runtime::kInlineOneByteSeqStringSetChar:
-      return ReduceSeqStringSetChar(node, String::ONE_BYTE_ENCODING);
     case Runtime::kInlineStringGetLength:
       return ReduceStringGetLength(node);
-    case Runtime::kInlineTwoByteSeqStringGetChar:
-      return ReduceSeqStringGetChar(node, String::TWO_BYTE_ENCODING);
-    case Runtime::kInlineTwoByteSeqStringSetChar:
-      return ReduceSeqStringSetChar(node, String::TWO_BYTE_ENCODING);
     case Runtime::kInlineValueOf:
       return ReduceValueOf(node);
     case Runtime::kInlineIsMinusZero:
@@ -336,44 +328,6 @@ Reduction JSIntrinsicLowering::ReduceMathSqrt(Node* node) {
 }
 
 
-Reduction JSIntrinsicLowering::ReduceSeqStringGetChar(
-    Node* node, String::Encoding encoding) {
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-  RelaxControls(node);
-  node->ReplaceInput(2, effect);
-  node->ReplaceInput(3, control);
-  node->TrimInputCount(4);
-  NodeProperties::ChangeOp(
-      node,
-      simplified()->LoadElement(AccessBuilder::ForSeqStringChar(encoding)));
-  return Changed(node);
-}
-
-
-Reduction JSIntrinsicLowering::ReduceSeqStringSetChar(
-    Node* node, String::Encoding encoding) {
-  // Note: The intrinsic has a strange argument order, so we need to reshuffle.
-  Node* index = NodeProperties::GetValueInput(node, 0);
-  Node* chr = NodeProperties::GetValueInput(node, 1);
-  Node* string = NodeProperties::GetValueInput(node, 2);
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-  ReplaceWithValue(node, string, node);
-  NodeProperties::RemoveType(node);
-  node->ReplaceInput(0, string);
-  node->ReplaceInput(1, index);
-  node->ReplaceInput(2, chr);
-  node->ReplaceInput(3, effect);
-  node->ReplaceInput(4, control);
-  node->TrimInputCount(5);
-  NodeProperties::ChangeOp(
-      node,
-      simplified()->StoreElement(AccessBuilder::ForSeqStringChar(encoding)));
-  return Changed(node);
-}
-
-
 Reduction JSIntrinsicLowering::ReduceStringGetLength(Node* node) {
   Node* value = NodeProperties::GetValueInput(node, 0);
   Node* effect = NodeProperties::GetEffectInput(node);