Add tests for obsolete issues

#KT-12126
 #KT-12189
 #KT-23628
 #KT-24209
 #KT-34338
 #KT-47279
 #KT-48498

compiler/testData/codegen/box/elvis/kt24209.kt

@@ -0,0 +1,14 @@
+// IGNORE_BACKEND: JVM
+
+interface Interface
+
+operator fun Interface.invoke(): String = "OK"
+
+class Class : Interface
+
+object Holder {
+    val value = Class()
+}
+
+fun box(): String =
+    Holder?.value()!!

compiler/testData/codegen/box/jvmField/kt12189_noClashOnDifferentCase.kt

@@ -0,0 +1,13 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
+// WITH_STDLIB
+
+abstract class Base {
+    @JvmField val name: String = "O"
+    @JvmField val Name: String = "K"
+}
+
+class Derived : Base()
+
+fun box(): String =
+    Derived().name + Derived().Name

compiler/testData/codegen/box/parametersMetadata/jvmOverloads.kt

@@ -0,0 +1,22 @@
+// SKIP_JDK6
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
+// WITH_STDLIB
+// FULL_JDK
+// PARAMETERS_METADATA
+// KT-23628
+
+class A @JvmOverloads constructor(x: String, y: Int = 42) {
+    @JvmOverloads
+    fun f(a: Long, b: Char = 'b') {}
+}
+
+fun box(): String {
+    val ctor = A::class.java.getDeclaredConstructor(String::class.java).parameters.toList()
+    if (ctor.toString() != "[java.lang.String x]") return "Fail constructor: $ctor"
+
+    val method = A::class.java.getDeclaredMethod("f", Long::class.java).parameters.toList()
+    if (method.toString() != "[long a]") return "Fail method: $method"
+
+    return "OK"
+}

compiler/testData/codegen/box/regressions/kt47279.kt

@@ -0,0 +1,8 @@
+fun test() {
+    null?.run { return }
+}
+
+fun box(): String {
+    test()
+    return "OK"
+}