Add tests on quick fix that adds 'actual' to platform declaration

#KT-18454

idea/testData/multiModuleQuickFix/addActualToClass/header/header.kt

@@ -0,0 +1 @@
+expect class Foo

idea/testData/multiModuleQuickFix/addActualToClass/header/header.kt.after

@@ -0,0 +1 @@
+expect class Foo

idea/testData/multiModuleQuickFix/addActualToClass/jvm/jvm.kt

@@ -0,0 +1,4 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+class <caret>Foo

idea/testData/multiModuleQuickFix/addActualToClass/jvm/jvm.kt.after

@@ -0,0 +1,4 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+actual class Foo

idea/testData/multiModuleQuickFix/addActualToClassMember/header/header.kt

@@ -0,0 +1,3 @@
+expect class Foo {
+    fun foo()
+}

idea/testData/multiModuleQuickFix/addActualToClassMember/header/header.kt.after

@@ -0,0 +1,3 @@
+expect class Foo {
+    fun foo()
+}

idea/testData/multiModuleQuickFix/addActualToClassMember/jvm/jvm.kt

@@ -0,0 +1,6 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+actual class Foo {
+    fun <caret>foo() {}
+}

idea/testData/multiModuleQuickFix/addActualToClassMember/jvm/jvm.kt.after

@@ -0,0 +1,6 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+actual class Foo {
+    actual fun foo() {}
+}

idea/testData/multiModuleQuickFix/addActualToTopLevelMember/header/header.kt

@@ -0,0 +1 @@
+expect fun foo()

idea/testData/multiModuleQuickFix/addActualToTopLevelMember/header/header.kt.after

@@ -0,0 +1 @@
+expect fun foo()

idea/testData/multiModuleQuickFix/addActualToTopLevelMember/jvm/jvm.kt

@@ -0,0 +1,4 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+fun <caret>foo() {}

idea/testData/multiModuleQuickFix/addActualToTopLevelMember/jvm/jvm.kt.after

@@ -0,0 +1,4 @@
+// "Add 'actual' modifier" "true"
+// ERROR: Declaration should be marked with 'actual' (suppress with -Xno-check-actual)
+
+actual fun foo() {}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiModuleTest.kt

@@ -189,4 +189,13 @@ class QuickFixMultiModuleTest : AbstractQuickFixMultiModuleTest() {
 
     @Test
     fun testImplementMembersInImplClassNonImplInheritor() = doMultiPlatformTest()
-}
+
+    @Test
+    fun testAddActualToClass() = doMultiPlatformTest()
+
+    @Test
+    fun testAddActualToClassMember() = doMultiPlatformTest()
+
+    @Test
+    fun testAddActualToTopLevelMember() = doMultiPlatformTest()
+}