[MCA] Add ReadState::dump (llvm#153345)

WriteState has a dump function that provides some helpful info for
debugging. Having this available in ReadState can be helpful as well in
some instances.

Author: boomanaiden154

llvm/include/llvm/MCA/Instruction.h

@@ -382,6 +382,10 @@ class ReadState {
   bool isReadZero() const { return IsZero; }
   void setReadZero() { IsZero = true; }
   void setPRF(unsigned ID) { PRFID = ID; }
+
+#ifndef NDEBUG
+  void dump() const;
+#endif
 };
 
 /// A sequence of cycles.

llvm/lib/MCA/Instruction.cpp

@@ -128,6 +128,13 @@ void WriteState::dump() const {
 }
 #endif
 
+#ifndef NDEBUG
+void ReadState::dump() const {
+  dbgs() << "{ OpIdx=" << RD->OpIndex << ", RegID " << getRegisterID()
+         << ", Cycles Left=" << CyclesLeft << " }";
+}
+#endif
+
 const CriticalDependency &Instruction::computeCriticalRegDep() {
   if (CriticalRegDep.Cycles)
     return CriticalRegDep;