[FIR] Update all required places according to changed overridden processing contract

This commit fixes all places that relied on the contract described in
  the previous commit and also updates corresponding tests

^KT-63738

compiler/testData/codegen/bytecodeText/falseSmartCast.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_K2: JVM_IR
 open class SuperFoo {
     public fun bar() {
         if (this is Foo) {
@@ -13,4 +12,4 @@ class Foo : SuperFoo()
 
 // 1 INVOKEVIRTUAL SuperFoo.baz
 // 0 CHECKCAST Foo
-// 0 INVOKEVIRTUAL Foo.baz
+// 0 INVOKEVIRTUAL Foo.baz