v.ast: add a mod field to ast.FnTypeDecl too

vlib/v/ast/ast.v

@@ -1522,6 +1522,7 @@ pub mut:
 pub struct FnTypeDecl {
 pub:
 	name          string
+	mod           string
 	is_pub        bool
 	typ           Type
 	pos           token.Pos

vlib/v/parser/parser.v

@@ -2782,6 +2782,7 @@ fn (mut p Parser) type_decl() ast.TypeDecl {
 		p.attrs = []
 		return ast.FnTypeDecl{
 			name:          fn_name
+			mod:           p.mod
 			is_pub:        is_pub
 			typ:           fn_type
 			pos:           decl_pos