Unwrap underlying typealias constructor earlier

The problem is very subtle (see the test): when generating a signature
for an object literal we also were mapping its super-class
(a type alias here).

Although we did unwrap its underlying constructor to map it properly
we did too late (after obtaining value parameters from the type alias constructor descriptor).

Another problem is that TypeAliasConstructorDescriptor.getOriginal
in the case does return itself, while it's expected to return
unsubstituted version

Note: everything works for common calls for such constructors
because they mapped through mapCallableMethod which contains
another custom unwrapping of type alias constructors

 #KT-16555 Fixed

compiler/testData/codegen/box/typealias/objectLiteralConstructor.kt

@@ -0,0 +1,10 @@
+open class LockFreeLinkedListNode(val s: String)
+private class SendBuffered(s: String) : LockFreeLinkedListNode(s)
+open class AddLastDesc2<out T : LockFreeLinkedListNode>(val node: T)
+typealias AddLastDesc<T> = AddLastDesc2<T>
+
+fun describeSendBuffered(): AddLastDesc<*> {
+    return object : AddLastDesc<SendBuffered>(SendBuffered("OK")) {}
+}
+
+fun box() = describeSendBuffered().node.s

compiler/testData/codegen/light-analysis/typealias/objectLiteralConstructor.txt

@@ -0,0 +1,24 @@
+@kotlin.Metadata
+public class AddLastDesc2 {
+    private final @org.jetbrains.annotations.NotNull field node: LockFreeLinkedListNode
+    public method <init>(@org.jetbrains.annotations.NotNull p0: LockFreeLinkedListNode): void
+    public final @org.jetbrains.annotations.NotNull method getNode(): LockFreeLinkedListNode
+}
+
+@kotlin.Metadata
+public class LockFreeLinkedListNode {
+    private final @org.jetbrains.annotations.NotNull field s: java.lang.String
+    public method <init>(@org.jetbrains.annotations.NotNull p0: java.lang.String): void
+    public final @org.jetbrains.annotations.NotNull method getS(): java.lang.String
+}
+
+@kotlin.Metadata
+public final class ObjectLiteralConstructorKt {
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+    public final static @org.jetbrains.annotations.NotNull method describeSendBuffered(): AddLastDesc2
+}
+
+@kotlin.Metadata
+final class SendBuffered {
+    public method <init>(@org.jetbrains.annotations.NotNull p0: java.lang.String): void
+}