Fix constant expression flagging in PDT evaluator.

Assets/Cryville/Common/Pdt/PdtEvaluatorBase.cs

@@ -30,11 +30,10 @@ namespace Cryville.Common.Pdt {
 			_revokepttconst = false;
 			for (_rip = exp.Instructions.First; _rip != null; _rip = _rip.Next)
 				_rip.Value.Execute(this);
-			if (!Operate(target, _framecount, true)) return false;
 			if (exp.IsPotentialConstant) {
 				exp.IsConstant = exp.IsPotentialConstant = !_revokepttconst;
 			}
-			return true;
+			return Operate(target, _framecount, true);
 		}
 		/// <summary>
 		/// Patches an expression with a lefthand variable and a compound operator.