CodeGen: Push the ModuleSlotTracker through MachineOperands

Push `ModuleSlotTracker` through `MachineOperand`s, dropping the time
for `llc -print-machineinstrs` on the testcase in PR23865 from ~13
seconds to ~9 seconds.  Now `SlotTracker::processFunctionMetadata()`
accounts for only 8% of the runtime, which seems reasonable.

llvm-svn: 240845

llvm/lib/CodeGen/MachineBasicBlock.cpp

@@ -305,7 +305,7 @@ void MachineBasicBlock::print(raw_ostream &OS, ModuleSlotTracker &MST,
     OS << '\t';
     if (I->isInsideBundle())
       OS << "  * ";
-    I->print(OS);
+    I->print(OS, MST);
   }
 
   // Print the successors of this block according to the CFG.