[turbofan] Add a debug_name to Parameter operators.

src/compiler/common-operator.h

Index: src/compiler/common-operator.h
diff --git a/src/compiler/common-operator.h b/src/compiler/common-operator.h
index 2d90e6489917d56bbe06e312015ef6942d60494a..a453b8159d62d242255eecfccbd30d4f6cfa4cb2 100644
--- a/src/compiler/common-operator.h
+++ b/src/compiler/common-operator.h
@@ -156,6 +156,27 @@ std::ostream& operator<<(std::ostream&, FrameStateCallInfo const&);
 size_t ProjectionIndexOf(const Operator* const);
 
 
+// The {IrOpcode::kParameter} opcode represents an incoming parameter to the
+// function. This class bundles the index and a debug name for such operators.
+class ParameterInfo final {
+ public:
+  ParameterInfo(int index, const char* debug_name)
+      : index_(index), debug_name_(debug_name) {}
+
+  int index() const { return index_; }
+  const char* debug_name() const { return debug_name_; }
+
+ private:
+  int index_;
+  const char* debug_name_;
+};
+
+std::ostream& operator<<(std::ostream&, ParameterInfo const&);
+
+int ParameterIndexOf(const Operator* const);
+const ParameterInfo& ParameterInfoOf(const Operator* const);
+
+
 // Interface for building common operators that can be used at any level of IR,
 // including JavaScript, mid-level, and low-level.
 class CommonOperatorBuilder final : public ZoneObject {
@@ -184,7 +205,7 @@ class CommonOperatorBuilder final : public ZoneObject {
   const Operator* Start(int num_formal_parameters);
   const Operator* Loop(int control_input_count);
   const Operator* Merge(int control_input_count);
-  const Operator* Parameter(int index);
+  const Operator* Parameter(int index, const char* debug_name = nullptr);
 
   const Operator* OsrNormalEntry();
   const Operator* OsrLoopEntry();