[CodeGen] Rename MachineInstrBuilder::addOperand. NFC

Rename from addOperand to just add, to match the other method that has been
added to MachineInstrBuilder for adding more than just 1 operand.

See https://reviews.llvm.org/D28057 for the whole discussion.

Differential Revision: https://reviews.llvm.org/D28556

llvm-svn: 291891
diff --git a/llvm/lib/Target/Hexagon/HexagonEarlyIfConv.cpp b/llvm/lib/Target/Hexagon/HexagonEarlyIfConv.cpp
index a5351cd..d7c726b 100644
--- a/llvm/lib/Target/Hexagon/HexagonEarlyIfConv.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonEarlyIfConv.cpp
@@ -680,12 +680,12 @@
     MachineInstrBuilder MIB = BuildMI(*ToB, At, DL, HII->get(COpc));
     MachineInstr::mop_iterator MOI = MI->operands_begin();
     if (HII->isPostIncrement(*MI)) {
-      MIB.addOperand(*MOI);
+      MIB.add(*MOI);
       ++MOI;
     }
     MIB.addReg(PredR);
     for (const MachineOperand &MO : make_range(MOI, MI->operands_end()))
-      MIB.addOperand(MO);
+      MIB.add(MO);
 
     // Set memory references.
     MachineInstr::mmo_iterator MMOBegin = MI->memoperands_begin();