EA-39175 Completion fails if MultiDeclaration is present on top level in file

idea/testData/completion/basic/InFileWithMultiDeclaration.kt

@@ -0,0 +1,12 @@
+data class LocalData(val first : Int, val second : Int)
+
+val (localFirst, localSecond) = LocalData(11, 12)
+
+fun test() {
+  local<caret>
+}
+
+// Test that this test won't fail with exception
+// Regression for EA-39175
+
+// ABSENT: localFirst, localSecond