[IR][NFC] Remove obsolete comments in BinaryOperator::swapOperands (llvm#125819)

Closes llvm#125438

Author: dtcxzyw

llvm/lib/IR/Instructions.cpp

@@ -2702,8 +2702,7 @@ BinaryOperator *BinaryOperator::CreateNot(Value *Op, const Twine &Name,
 
 // Exchange the two operands to this instruction. This instruction is safe to
 // use on any binary instruction and does not modify the semantics of the
-// instruction. If the instruction is order-dependent (SetLT f.e.), the opcode
-// is changed.
+// instruction.
 bool BinaryOperator::swapOperands() {
   if (!isCommutative())
     return true; // Can't commute operands