Add regression tests for obsolete issues

#KT-9304
 #KT-14961
 #KT-16549
 #KT-21080
 #KT-28234
 #KT-30102
 #KT-31994
 #KT-34291
 #KT-38099
 #KT-41174
 #KT-44622
 #KT-44701
 #KT-44781
 #KT-44849
 #KT-44978
 #KT-45081
 #KT-45286
 #KT-45383
 #KT-45444
 #KT-45907

compiler/testData/codegen/box/inlineClasses/kt31994.kt

@@ -0,0 +1,15 @@
+// IGNORE_BACKEND: JVM
+// IGNORE_LIGHT_ANALYSIS
+
+fun box(): String =
+    testBug(null)
+
+fun testBug(test: Test?): String =
+    test?.Inner()?.thing ?: "OK"
+
+class Test(val name: String) {
+    inner class Inner {
+        val thing: String
+            get() = name
+    }
+}