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

compiler/testData/diagnostics/tests/smartCasts/extensionSafeCall.fir.kt

@@ -0,0 +1,13 @@
+class Your
+
+fun Your.foo() = Any()
+
+fun <T> T?.let(f: (T) -> Unit) {
+    if (this != null) f(this)
+}
+
+fun test(your: Your?) {
+    (your?.foo() as? Any)?.let {}
+    // strange smart cast to 'Your' at this point
+    your.<!INAPPLICABLE_CANDIDATE!>hashCode<!>()
+}