getQualifiedExpressionTypeInfo refactoring

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/CallExpressionResolver.kt

@@ -275,16 +275,8 @@ class CallExpressionResolver(
         return noTypeInfo(context)
     }
 
-    /**
+    private fun KtQualifiedExpression.elementChain(context: ExpressionTypingContext) =
-     * Visits a qualified expression like x.y or x?.z controlling data flow information changes.
+            qualifiedExpressionResolver.resolveQualifierInExpressionAndUnroll(this, context) {
-
-     * @return qualified expression type together with data flow information
-     */
-    fun getQualifiedExpressionTypeInfo(expression: KtQualifiedExpression, context: ExpressionTypingContext): KotlinTypeInfo {
-        val currentContext = context.replaceExpectedType(NO_EXPECTED_TYPE).replaceContextDependency(INDEPENDENT)
-        val trace = currentContext.trace
-
-        val elementChain = qualifiedExpressionResolver.resolveQualifierInExpressionAndUnroll(expression, context) {
                 nameExpression ->
                 val temporaryForVariable = TemporaryTraceAndCache.create(
                         context, "trace to resolve as local variable or property", nameExpression)
@@ -303,8 +295,17 @@ class CallExpressionResolver(
                 }
             }
 
-        val firstElement = elementChain.first()
+    /**
-        val firstReceiver = firstElement.receiver
+     * Visits a qualified expression like x.y or x?.z controlling data flow information changes.
+
+     * @return qualified expression type together with data flow information
+     */
+    fun getQualifiedExpressionTypeInfo(expression: KtQualifiedExpression, context: ExpressionTypingContext): KotlinTypeInfo {
+        val currentContext = context.replaceExpectedType(NO_EXPECTED_TYPE).replaceContextDependency(INDEPENDENT)
+        val trace = currentContext.trace
+
+        val elementChain = expression.elementChain(context)
+        val firstReceiver = elementChain.first().receiver
 
         var receiverTypeInfo = when (trace.get(BindingContext.QUALIFIER, firstReceiver)) {
             null -> expressionTypingServices.getTypeInfo(firstReceiver, currentContext)