[FIR2IR] Support type aliases properly

compiler/testData/ir/irText/declarations/annotations/typeAliasesWithAnnotations.fir.txt

@@ -1,4 +1,5 @@
 FILE fqName:<root> fileName:/typeAliasesWithAnnotations.kt
+  TYPEALIAS name:TestTypeAlias visibility:public expandedType:kotlin.String
   CLASS ANNOTATION_CLASS name:TestAnn modality:FINAL visibility:public superTypes:[kotlin.Annotation]
     annotations:
       Target(allowedTargets = GET_ENUM 'ENUM_ENTRY IR_EXTERNAL_DECLARATION_STUB name:TYPEALIAS' type=kotlin.annotation.AnnotationTarget)

compiler/testData/ir/irText/declarations/fileWithTypeAliasesOnly.fir.txt

@@ -1 +0,0 @@
-FILE fqName:<root> fileName:/fileWithTypeAliasesOnly.kt

compiler/testData/ir/irText/declarations/fileWithTypeAliasesOnly.kt

@@ -1 +1,2 @@
+// FIR_IDENTICAL
 typealias Bar<T> = (T) -> String

compiler/testData/ir/irText/declarations/typeAlias.fir.txt

@@ -1,4 +1,5 @@
 FILE fqName:<root> fileName:/typeAlias.kt
+  TYPEALIAS name:Test1 visibility:public expandedType:kotlin.String
   FUN name:foo visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=null