Add tests for obsolete issues

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

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