making LambdaArgument methods nullable

overridden `LambdaArgument.getArgumentExpression` removed because it is already nullable in parent

#EA-117013

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ErrorExpressionGenerator.kt

@@ -50,17 +50,13 @@ class ErrorExpressionGenerator(statementGenerator: StatementGenerator) : Stateme
             receiverExpression.genExpr()
         }
 
-        ktCall.valueArguments.forEach {
+        (ktCall.valueArguments + ktCall.lambdaArguments).forEach {
             val ktArgument = it.getArgumentExpression()
             if (ktArgument != null) {
                 irErrorCall.addArgument(ktArgument.genExpr())
             }
         }
 
-        ktCall.lambdaArguments.forEach {
-            irErrorCall.addArgument(it.getArgumentExpression().genExpr())
-        }
-
         irErrorCall
     }