Add tests for merging SAM wrappers and references

compiler/testData/codegen/bytecodeText/sam/samWrapperOfReference.kt

@@ -0,0 +1,23 @@
+// This optimization is only done by the JVM_IR backend.
+// IGNORE_BACKEND: JVM
+// FILE: JFoo.java
+
+public class JFoo {
+    public static void foo(Runnable f) {
+        f.run();
+    }
+}
+
+// FILE: Test.kt
+class A {
+    fun f() {}
+}
+
+fun test() {
+    JFoo.foo(A()::f)
+}
+
+// Referenced function called from run(), no wrapper class generated:
+// 1 NEW A
+// 2 NEW
+// 0 INVOKEINTERFACE