Minor: add dummy.kt to some IC tests

This makes it impossible to pass the tests
by rebuilding everything.

jps-plugin/testData/incremental/classHierarchyAffected/classBecameInterface/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/classHierarchyAffected/companionObjectMemberChanged/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/classHierarchyAffected/companionObjectToSimpleObject/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/classHierarchyAffected/propertyNullabilityChanged/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/pureKotlin/changeTypeImplicitlyWithCircularDependency/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/pureKotlin/classSignatureChanged/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/pureKotlin/fileWithInlineFunctionRemoved/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/pureKotlin/functionBecameInline/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}

jps-plugin/testData/incremental/pureKotlin/privateConstantsChanged/dummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun dummy() {}