KT-2193 Nullability information lost for functions inherited from traits

#KT-2193 fixed

compiler/testData/readKotlinBinaryClass/classFun/FunDelegationToTraitImpl.kt

@@ -0,0 +1,9 @@
+package test
+
+// test composed from KT-2193
+
+trait A {
+    open fun f(): String = "test"
+}
+
+class B() : A

compiler/testData/readKotlinBinaryClass/classFun/FunDelegationToTraitImpl.txt

@@ -0,0 +1,9 @@
+namespace test
+
+abstract trait test.A : jet.Any {
+    open fun f(): jet.String
+}
+final class test.B : test.A {
+    final /*constructor*/ fun <init>(): test.B
+    open override /*1*/ fun f(): jet.String
+}

compiler/testData/readKotlinBinaryClass/prop/VarDelegationToTraitImpl.kt

@@ -0,0 +1,13 @@
+package test
+
+// test composed from KT-2193
+
+trait A {
+    open var v: String
+        get() = "test"
+        set(value) {
+            throw UnsupportedOperationException()
+        }
+}
+
+class B() : A

compiler/testData/readKotlinBinaryClass/prop/VarDelegationToTraitImpl.txt

@@ -0,0 +1,9 @@
+namespace test
+
+abstract trait test.A : jet.Any {
+    open var v: jet.String
+}
+final class test.B : test.A {
+    final /*constructor*/ fun <init>(): test.B
+    open var v: jet.String
+}