Fix type arguments mapping

compiler/testData/ir/irText/declarations/parameters/dataClassMembers.txt

@@ -59,7 +59,7 @@ FILE fqName:<root> fileName:/dataClassMembers.kt
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='copy(T = ..., String = ...): Test<T>'
           CALL 'constructor Test(T, String = ...)' type=Test<T> origin=null
-            <T>: null
+            <T>: T
             x: GET_VAR 'value-parameter x: T = ...' type=T origin=null
             y: GET_VAR 'value-parameter y: String = ...' type=kotlin.String origin=null
     FUN GENERATED_DATA_CLASS_MEMBER name:toString visibility:public modality:OPEN <> ($this:Test<T>) returnType:String flags:

compiler/testData/ir/irText/declarations/parameters/delegatedMembers.txt

@@ -58,7 +58,7 @@ FILE fqName:<root> fileName:/delegatedMembers.kt
       VALUE_PARAMETER name:x index:1 type:X flags:
       BLOCK_BODY
         CALL 'qux(TT, X): Unit' type=kotlin.Unit origin=null
-          <X>: null
+          <X>: X
           $this: GET_FIELD '`Test$IBase$delegate`: IBase<TT>' type=IBase<TT> origin=null
             receiver: GET_VAR 'this@Test: Test<TT>' type=Test<TT> origin=null
           t: GET_VAR 'value-parameter t: TT' type=TT origin=null