[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/syntheticExtensions/javaProperties/ImplicitReceiver.fir.kt

@@ -0,0 +1,12 @@
+// FILE: KotlinFile.kt
+fun JavaClass.foo() {
+    useInt(getSomething())
+    useInt(something)
+}
+
+fun useInt(i: Int) {}
+
+// FILE: JavaClass.java
+public class JavaClass {
+    public int getSomething() { return 1; }
+}