[turbofan] Introduce lazy bailout, masked as a call.

src/compiler/ppc/instruction-selector-ppc.cc

Index: src/compiler/ppc/instruction-selector-ppc.cc
diff --git a/src/compiler/ppc/instruction-selector-ppc.cc b/src/compiler/ppc/instruction-selector-ppc.cc
index 5b3008b91eb8f97c99ca33a9d95f29151b22d4bf..a0bfb24cc62f1acd01e563230e62dc1b5038f349 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -1545,7 +1545,7 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
   }
 
   // Select the appropriate opcode based on the call type.
-  InstructionCode opcode;
+  InstructionCode opcode = kArchNop;
   switch (descriptor->kind()) {
     case CallDescriptor::kCallAddress:
       opcode =
@@ -1558,9 +1558,9 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
     case CallDescriptor::kCallJSFunction:
       opcode = kArchCallJSFunction | MiscField::encode(flags);
       break;
-    default:
-      UNREACHABLE();
-      return;
+    case CallDescriptor::kLazyBailout:
+      opcode = kArchLazyBailout | MiscField::encode(flags);
+      break;
   }
 
   // Emit the call instruction.