[turbofan] Fix bounds check elimination for safe-integer-add.

Bug: chromium:760434
Change-Id: I95bcf33f334349de0a81f574ba64128b8e1b2ebd
Reviewed-on: https://chromium-review.googlesource.com/643192
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47723}

src/compiler/redundancy-elimination.cc

@@ -42,6 +42,8 @@ Reduction RedundancyElimination::Reduce(Node* node) {
       return ReduceCheckNode(node);
     case IrOpcode::kSpeculativeNumberAdd:
     case IrOpcode::kSpeculativeNumberSubtract:
+    case IrOpcode::kSpeculativeSafeIntegerAdd:
+    case IrOpcode::kSpeculativeSafeIntegerSubtract:
       // For increments and decrements by a constant, try to learn from the last
       // bounds check.
       return TryReuseBoundsCheckForFirstInput(node);
@@ -192,7 +194,9 @@ Reduction RedundancyElimination::ReduceCheckNode(Node* node) {
 
 Reduction RedundancyElimination::TryReuseBoundsCheckForFirstInput(Node* node) {
   DCHECK(node->opcode() == IrOpcode::kSpeculativeNumberAdd ||
-         node->opcode() == IrOpcode::kSpeculativeNumberSubtract);
+         node->opcode() == IrOpcode::kSpeculativeNumberSubtract ||
+         node->opcode() == IrOpcode::kSpeculativeSafeIntegerAdd ||
+         node->opcode() == IrOpcode::kSpeculativeSafeIntegerSubtract);
 
   DCHECK_EQ(1, node->op()->EffectInputCount());
   DCHECK_EQ(1, node->op()->EffectOutputCount());