[turbofan] Add DebugBreak machine operator and support

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 88cc2e536cfe5345f54f4f04a7e3693caa660316..92223e87a0e4b9cf232512740c1d4a6f239f807e 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -900,6 +900,9 @@ void InstructionSelector::VisitNode(Node* node) {
     case IrOpcode::kStateValues:
     case IrOpcode::kObjectState:
       return;
+    case IrOpcode::kDebugBreak:
+      VisitDebugBreak();
+      return;
     case IrOpcode::kLoad: {
       LoadRepresentation type = LoadRepresentationOf(node->op());
       MarkAsRepresentation(type.representation(), node);
@@ -1785,6 +1788,10 @@ void InstructionSelector::VisitThrow(Node* value) {
   Emit(kArchThrowTerminator, g.NoOutput());
 }
 
+void InstructionSelector::VisitDebugBreak() {
+  OperandGenerator g(this);
+  Emit(kArchDebugBreak, g.NoOutput());
+}
 
 FrameStateDescriptor* InstructionSelector::GetFrameStateDescriptor(
     Node* state) {