Introduce subject to when: suggest for qualified, not for obj / constant

#KT-18772 Fixed

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified.kt

@@ -0,0 +1,13 @@
+import Platform.JvmPlatform
+
+sealed class Platform {
+    object JvmPlatform : Platform()
+    class Another(val name: String) : Platform()
+}
+
+class ModuleInfo(val platform: Platform)
+
+fun foo(moduleInfo: ModuleInfo) = <caret>when {
+    moduleInfo.platform == JvmPlatform -> 1
+    else -> 0
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified.kt.after

@@ -0,0 +1,13 @@
+import Platform.JvmPlatform
+
+sealed class Platform {
+    object JvmPlatform : Platform()
+    class Another(val name: String) : Platform()
+}
+
+class ModuleInfo(val platform: Platform)
+
+fun foo(moduleInfo: ModuleInfo) = <caret>when (moduleInfo.platform) {
+    JvmPlatform -> 1
+    else -> 0
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified2.kt

@@ -0,0 +1,13 @@
+import Platform.JvmPlatform
+
+sealed class Platform {
+    object JvmPlatform : Platform()
+    class Another(val name: String) : Platform()
+}
+
+class ModuleInfo(val platform: Platform)
+
+fun foo(moduleInfo: ModuleInfo) = <caret>when {
+    JvmPlatform == moduleInfo.platform -> 1
+    else -> 0
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified2.kt.after

@@ -0,0 +1,13 @@
+import Platform.JvmPlatform
+
+sealed class Platform {
+    object JvmPlatform : Platform()
+    class Another(val name: String) : Platform()
+}
+
+class ModuleInfo(val platform: Platform)
+
+fun foo(moduleInfo: ModuleInfo) = <caret>when (moduleInfo.platform) {
+    JvmPlatform -> 1
+    else -> 0
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified3.kt

@@ -0,0 +1,11 @@
+class Foo {
+    val bar = 1
+}
+
+fun test(foo: Foo): Int {
+    return <caret>when {
+        foo.bar == 1 -> 10
+        foo.bar == 2 -> 20
+        else -> 30
+    }
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified3.kt.after

@@ -0,0 +1,11 @@
+class Foo {
+    val bar = 1
+}
+
+fun test(foo: Foo): Int {
+    return <caret>when (foo.bar) {
+        1 -> 10
+        2 -> 20
+        else -> 30
+    }
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified4.kt

@@ -0,0 +1,14 @@
+class Foo {
+    val bar = 1
+}
+
+const val A = 1
+const val B = 2
+
+fun test(foo: Foo): Int {
+    return <caret>when {
+        A == foo.bar -> 10
+        B == foo.bar -> 20
+        else -> 30
+    }
+}

idea/testData/inspectionsLocal/branched/introduceWhenSubject/qualified4.kt.after

@@ -0,0 +1,14 @@
+class Foo {
+    val bar = 1
+}
+
+const val A = 1
+const val B = 2
+
+fun test(foo: Foo): Int {
+    return <caret>when (foo.bar) {
+        A -> 10
+        B -> 20
+        else -> 30
+    }
+}