[turbofan] Properly hook up string operators in the effect/control chain.

The string operators not only read memory, but also write memory in case
of cons string flattening, so we better make sure to have the stub calls
in the effect chain.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/1938383002
Cr-Commit-Position: refs/heads/master@{#35965}

src/compiler/simplified-lowering.cc

@@ -1041,7 +1041,8 @@ class RepresentationSelector {
         VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
         if (lower()) {
           // StringEqual(x, y) => Call(StringEqualStub, x, y, no-context)
-          Operator::Properties properties = node->op()->properties();
+          Operator::Properties properties =
+              Operator::kCommutative | Operator::kNoThrow;
           Callable callable = CodeFactory::StringEqual(jsgraph_->isolate());
           CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
           CallDescriptor* desc = Linkage::GetStubCallDescriptor(
@@ -1050,6 +1051,8 @@ class RepresentationSelector {
           node->InsertInput(jsgraph_->zone(), 0,
                             jsgraph_->HeapConstant(callable.code()));
           node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
           NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
         }
         break;
@@ -1058,7 +1061,7 @@ class RepresentationSelector {
         VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
         if (lower()) {
           // StringLessThan(x, y) => Call(StringLessThanStub, x, y, no-context)
-          Operator::Properties properties = node->op()->properties();
+          Operator::Properties properties = Operator::kNoThrow;
           Callable callable = CodeFactory::StringLessThan(jsgraph_->isolate());
           CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
           CallDescriptor* desc = Linkage::GetStubCallDescriptor(
@@ -1067,6 +1070,8 @@ class RepresentationSelector {
           node->InsertInput(jsgraph_->zone(), 0,
                             jsgraph_->HeapConstant(callable.code()));
           node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
           NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
         }
         break;
@@ -1076,7 +1081,7 @@ class RepresentationSelector {
         if (lower()) {
           // StringLessThanOrEqual(x, y)
           //   => Call(StringLessThanOrEqualStub, x, y, no-context)
-          Operator::Properties properties = node->op()->properties();
+          Operator::Properties properties = Operator::kNoThrow;
           Callable callable =
               CodeFactory::StringLessThanOrEqual(jsgraph_->isolate());
           CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
@@ -1086,6 +1091,8 @@ class RepresentationSelector {
           node->InsertInput(jsgraph_->zone(), 0,
                             jsgraph_->HeapConstant(callable.code()));
           node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
           NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
         }
         break;
@@ -1094,7 +1101,7 @@ class RepresentationSelector {
         VisitUnop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
         if (lower()) {
           // StringToNumber(x) => Call(StringToNumberStub, x, no-context)
-          Operator::Properties properties = node->op()->properties();
+          Operator::Properties properties = Operator::kNoThrow;
           Callable callable = CodeFactory::StringToNumber(jsgraph_->isolate());
           CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
           CallDescriptor* desc = Linkage::GetStubCallDescriptor(
@@ -1103,6 +1110,8 @@ class RepresentationSelector {
           node->InsertInput(jsgraph_->zone(), 0,
                             jsgraph_->HeapConstant(callable.code()));
           node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
+          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
           NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
         }
         break;