[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/CodeGen/XRayInstrumentation.cpp b/llvm/lib/CodeGen/XRayInstrumentation.cpp
index 63bd762..760683b 100644
--- a/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -81,7 +81,7 @@
         auto MIB = BuildMI(MBB, T, T.getDebugLoc(), TII->get(Opc))
                        .addImm(T.getOpcode());
         for (auto &MO : T.operands())
-          MIB.addOperand(MO);
+          MIB.add(MO);
         Terminators.push_back(&T);
       }
     }