Minor. Merge multiplatformTypeRefinement testdata with multiplatform testdata

idea/testData/multiplatform/diamondModuleDependency2/common-2-2/common-2-2.kt

@@ -0,0 +1,10 @@
+@file:Suppress("UNUSED_PARAMETER")
+package sample
+
+expect interface C : A {
+    fun foo_C_1()
+}
+
+fun take1(x: C): CC = null!!
+
+fun getC(): C = null!!