K2: Add new tests for PCLA implementation

Many of them have been found & minimized at FP tests/user projects

^KT-59791 Fixed

compiler/testData/diagnostics/tests/inference/builderInference/smartCastOnBuilderController.kt

@@ -0,0 +1,18 @@
+class Controller<T2>
+
+fun <T1> generate(
+    block: (Controller<T1>) -> Unit
+): T1 = TODO()
+
+fun <E3> foobar(
+    cont: Controller<E3>
+) {}
+
+fun foo() {
+    generate { cont ->
+        foobar(cont as Controller<String>)
+        baz(cont)
+    }
+}
+
+fun baz(cont: Controller<String>) {}