Quick fix renamed: ChangePrivateTopLevelToInternal --> IncreaseVisibility

idea/testData/quickfix/increaseVisibility/privateTopLevelVarWithSetterInFile.after.kt

@@ -0,0 +1,8 @@
+// "Make <set-prop> internal" "true"
+// ERROR: Cannot assign to 'prop': the setter is private in file
+
+package test
+
+fun foo() {
+    prop = 20
+}