Refactor multiplatform test cases in MultiModuleHighlightingTest

Groupt multiplatform test cases in a nested class, get rid of duplicated
code, rename "header" -> "common" where it relates to the common module

idea/testData/multiModuleHighlighting/multiplatform/basic/common/common.kt

@@ -0,0 +1,3 @@
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] Header declaration 'My' has no implementation in module for JVM">My</error> {
+
+}

idea/testData/multiModuleHighlighting/multiplatform/basic/jvm/jvm.kt

@@ -0,0 +1,15 @@
+<error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> class Your {
+
+}
+
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] Header declaration 'His' has no implementation in module for JVM">His</error> {
+
+}
+
+header class Their {
+
+}
+
+impl class Their {
+
+}

idea/testData/multiModuleHighlighting/multiplatform/headerClass/common/common.kt

@@ -0,0 +1,3 @@
+header class My {
+
+}

idea/testData/multiModuleHighlighting/multiplatform/headerClass/jvm/jvm.kt

@@ -0,0 +1,3 @@
+impl class My {
+
+}

idea/testData/multiModuleHighlighting/multiplatform/headerFunctionProperty/common/common.kt

@@ -0,0 +1,3 @@
+header fun foo(): Int
+
+header val bar: String

idea/testData/multiModuleHighlighting/multiplatform/headerFunctionProperty/jvm/jvm.kt

@@ -0,0 +1,3 @@
+impl fun foo() = 42
+
+impl val bar = "Hello"

idea/testData/multiModuleHighlighting/multiplatform/headerPartiallyImplemented/common/common.kt

@@ -0,0 +1,23 @@
+header class <error>My</error> {
+
+    fun foo(): Int
+
+    fun bar(arg: Int): Boolean
+
+}
+
+header class <error>Your</error> {
+
+    fun foo(): Int
+
+    fun bar(arg: Int): Boolean
+
+}
+
+header class His {
+
+    fun foo(): Int
+
+    fun bar(arg: Int): Boolean
+
+}

idea/testData/multiModuleHighlighting/multiplatform/headerPartiallyImplemented/jvm/jvm.kt

@@ -0,0 +1,20 @@
+<error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> class My {
+
+    <error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> fun foo() = 42
+}
+
+<error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> class Your {
+
+    <error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> fun foo() = 13
+
+    <error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> fun bar(arg: Int) = arg
+
+}
+
+impl class His {
+
+    impl fun foo() = 7
+
+    impl fun bar(arg: Int) = arg == foo()
+
+}

idea/testData/multiModuleHighlighting/multiplatform/headerWithoutImplForBoth/common/common.kt

@@ -0,0 +1,3 @@
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] Header declaration 'My' has no implementation in module for JS"><error descr="[HEADER_WITHOUT_IMPLEMENTATION] Header declaration 'My' has no implementation in module for JVM">My</error></error> {
+
+}

idea/testData/multiModuleHighlighting/multiplatform/suppressHeaderWithoutImpl/common/common.kt

@@ -0,0 +1,7 @@
+// See KT-15601
+
+@Suppress("HEADER_WITHOUT_IMPLEMENTATION")
+header interface Event
+
+@Suppress("SOMETHING_WRONG")
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] Header declaration 'Wrong' has no implementation in module for JVM">Wrong</error>