[llvm-mca] remove unused argument from method InstrBuilder::createInstrDescImpl.

We don't need to pass the instruction index to the method that constructs new
instruction descriptors.

No functional change intended.

llvm-svn: 331516
diff --git a/llvm/tools/llvm-mca/InstrBuilder.h b/llvm/tools/llvm-mca/InstrBuilder.h
index 30af1bf..c22b7dc 100644
--- a/llvm/tools/llvm-mca/InstrBuilder.h
+++ b/llvm/tools/llvm-mca/InstrBuilder.h
@@ -41,7 +41,10 @@
 
   llvm::DenseMap<unsigned short, std::unique_ptr<const InstrDesc>> Descriptors;
 
-  void createInstrDescImpl(const llvm::MCInst &MCI);
+  const InstrDesc &createInstrDescImpl(const llvm::MCInst &MCI);
+
+  InstrBuilder(const InstrBuilder &) = delete;
+  InstrBuilder &operator=(const InstrBuilder &) = delete;
 
 public:
   InstrBuilder(const llvm::MCSubtargetInfo &sti, const llvm::MCInstrInfo &mcii)
@@ -59,8 +62,7 @@
     return ProcResourceMasks;
   }
 
-  std::unique_ptr<Instruction> createInstruction(unsigned Idx,
-                                                 const llvm::MCInst &MCI);
+  std::unique_ptr<Instruction> createInstruction(const llvm::MCInst &MCI);
 };
 } // namespace mca