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

compiler/testData/diagnostics/tests/controlStructures/kt4310.fir.kt

@@ -0,0 +1,12 @@
+// !WITH_NEW_INFERENCE
+package f
+
+fun test(a: Boolean, b: Boolean): Int {
+    return if(a) {
+        1
+    } else {
+        if (b) {
+            3
+        }
+    }
+}