[KLIB][tests] Keep "klib evolution" test data under "testData/klib/" dir

compiler/testData/klib/evolution/addOverloads.kt

@@ -0,0 +1,62 @@
+// MODULE: lib
+// FILE: A.kt
+// VERSION: 1
+
+class X {
+    fun foo(s: String): String = "initial overload $s"
+    fun bar(s: String?): String = "initial nullable overload $s"
+    fun qux(s: Any): String = "initial any overload $s"
+}
+
+fun foo(s: String): String = "initial overload $s"
+fun bar(s: String?): String = "initial nullable overload $s"
+fun qux(s: Any): String = "initial any overload $s"
+
+// FILE: B.kt
+// VERSION: 2
+
+class X {
+    fun foo(): String = "no arg overload"
+    fun foo(s: String): String = "initial overload $s"
+    fun foo(s: String?): String = "nullable overload $s"
+    fun foo(s: String, p: String): String = "more args overload $s"
+
+    fun bar(s: String?): String = "initial overload $s"
+    fun bar(s: String): String = "non-nullable overload $s"
+    
+    fun qux(s: Any): String = "initial any overload $s"
+    fun qux(s: String): String = "initial narrower overload $s"
+}
+
+fun foo(): String = "no arg overload"
+fun foo(s: String): String = "initial overload $s"
+fun foo(s: String?): String = "nullable overload $s"
+fun foo(s: String, p: String): String = "more args overload $s"
+
+fun bar(s: String?): String = "initial overload $s"
+fun bar(s: String): String = "non-nullable overload $s"
+
+fun qux(s: Any): String = "initial any overload $s"
+fun qux(s: String): String = "initial narrower overload $s"
+
+// MODULE: mainLib(lib)
+// FILE: mainLib.kt
+
+val x = X()
+
+fun lib(): String = when {
+    x.foo("first") != "initial overload first" -> "fail 1"
+    x.bar("second") != "initial overload second" -> "fail 2"
+    x.qux("third") != "initial any overload third" -> "fail 3"
+
+    foo("first") != "initial overload first" -> "fail 4"
+    bar("second") != "initial overload second" -> "fail 5"
+    qux("third") != "initial any overload third" -> "fail 6"
+
+    else -> "OK"
+}
+
+// MODULE: main(mainLib)
+// FILE: main.kt
+fun box(): String = lib()
+