[FIR-TEST] Move analysis tests to separate module

compiler/fir/analysis-tests/testData/resolve/smartcasts/receivers/implicitReceiverAsWhenSubject.kt

@@ -0,0 +1,18 @@
+// !DUMP_CFG
+fun Any.test_1(): Int = when (this) {
+    is List<*> -> this.size
+    is String -> length
+    else -> 0
+}
+
+fun Any.test_2(): Int = when (val x = this) {
+    is List<*> -> {
+        x.size
+        this.size
+    }
+    is String -> {
+        x.length
+        length
+    }
+    else -> 0
+}