[Test] Add regression tests for issues which are fixed in K2

Related issues:
KT-10879, KT-18055, KT-20617, KT-23873
KT-25668, KT-31191, KT-33108, KT-41013
KT-51827, KT-53886, KT-56624, KT-58447
KT-58458, KT-58751, KT-58814, KT-60597
KT-62806, KT-63258, KT-63444, KT-65101
KT-65408, KT-65844, KT-66186

^KT-65926 Fixed

compiler/testData/codegen/box/functions/lambdaWithTwoContextReceivers.kt

@@ -0,0 +1,27 @@
+// LANGUAGE: +ContextReceivers
+// TARGET_BACKEND: JVM_IR
+// WITH_STDLIB
+// ISSUE: KT-52887
+
+interface SnarkRoute {
+    context(PageContext)
+    fun route(route: String, block: context(PageContext, SnarkRoute) () -> Unit)
+}
+
+context(PageContext)
+fun SnarkRoute.pagesFrom() {
+    route("") {
+        get {
+
+        }
+    }
+}
+
+data class PageContext(val context: String)
+
+
+fun SnarkRoute.get(foo: ()-> Unit) {}
+
+fun box(): String {
+    return "OK"
+}

compiler/testData/codegen/box/inference/safeCastWithElvis.kt

@@ -0,0 +1,10 @@
+// WITH_STDLIB
+// IGNORE_BACKEND_K1: JS_IR, JS_IR_ES6, WASM, NATIVE
+// ISSUE: KT-62806
+
+fun <T: Number> foo(x: Number) = x as? T ?: TODO()
+val x: Int? = foo<Int>(1)
+
+fun box(): String {
+    return if (x == 1) "OK" else "Fail: $x"
+}

compiler/testData/codegen/box/lambda/ifWithReferenceAndLambda.kt

@@ -0,0 +1,25 @@
+// IGNORE_BACKEND_K1: ANY
+// WITH_STDLIB
+// ISSUE: KT-63258
+
+class MethodReferenceNPE() {
+    private val singleRef: () -> Unit =
+        1.let {
+            if (it == 0) {
+                { }
+            } else {
+                this@MethodReferenceNPE::myMethod
+            }
+        }
+
+    private fun myMethod() {}
+
+    fun run() {
+        singleRef()
+    }
+}
+
+fun box(): String {
+    MethodReferenceNPE().run()
+    return "OK"
+}