Introduce Variable: Fix NPE for the case of statement-like expression

#KT-8054 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/AbstractKotlinInplaceIntroducer.kt

@@ -37,7 +37,7 @@ import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
 import java.awt.BorderLayout
 
 public abstract class AbstractKotlinInplaceIntroducer<D: JetNamedDeclaration>(
-        expression: JetExpression,
+        expression: JetExpression?,
         occurrences: Array<JetExpression>,
         title: String,
         project: Project,
@@ -58,7 +58,7 @@ public abstract class AbstractKotlinInplaceIntroducer<D: JetNamedDeclaration>(
             stopIntroduce(myEditor)
             myProject.executeWriteCommand(getCommandName(), getCommandName(), action)
             // myExprMarker was invalidated by stopIntroduce()
-            myExprMarker = createMarker(myExpr)
+            myExprMarker = myExpr?.let { createMarker(it) }
             startInplaceIntroduceTemplate()
         }
         finally {

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceVariable/KotlinIntroduceVariableHandler.java

@@ -206,7 +206,6 @@ public class KotlinIntroduceVariableHandler extends KotlinIntroduceHandlerBase {
                         expression, suggestedNames, allReplaces, commonContainer,
                         commonParent, replaceOccurrence, propertyRef, references,
                         reference, finalNoTypeInference, expressionType, bindingContext);
-                final boolean finalReplaceOccurrence = replaceOccurrence;
                 CommandProcessor.getInstance().executeCommand(project, new Runnable() {
                     @Override
                     public void run() {

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceVariable/KotlinVariableInplaceIntroducer.kt

@@ -42,7 +42,7 @@ import java.awt.BorderLayout
 
 public class KotlinVariableInplaceIntroducer(
         val addedVariable: JetProperty,
-        val originalExpression: JetExpression,
+        val originalExpression: JetExpression?,
         val occurrencesToReplace: Array<JetExpression>,
         val suggestedNames: Array<out String>,
         val isVar: Boolean,