Iniital implementation of synthetic extensions for SAM-adapter functions (non-static only)

compiler/testData/diagnostics/tests/syntheticExtensions/javaProperties/SmartCastImplicitReceiver.kt

@@ -0,0 +1,23 @@
+// FILE: KotlinFile.kt
+fun Any.foo(): Int {
+    if (this is JavaClass) {
+        something++
+        return x
+    }
+    return 0
+}
+
+// FILE: JavaClass.java
+public abstract class JavaClass extends BaseClass implements JavaInterface {
+    public int getSomething() { return 1; }
+    public void setSomething(int value) { }
+}
+
+// FILE: BaseClass.java
+public abstract class BaseClass implements JavaInterface {
+}
+
+// FILE: JavaInterface.java
+public interface JavaInterface {
+    int getX();
+}