predlib.lsp: fix type comparisons involving gray streams

Due to gray:fundamental-stream being treated as a built-in type,
subclass relationships were not checked (see added test case).
Fixes #614.

src/lsp/predlib.lsp

@@ -1351,7 +1351,6 @@ if not possible."
                (EXT:ANSI-STREAM (OR BROADCAST-STREAM CONCATENATED-STREAM ECHO-STREAM
                                  FILE-STREAM STRING-STREAM SYNONYM-STREAM TWO-WAY-STREAM
                                  EXT:SEQUENCE-STREAM))
-               #+clos-streams (GRAY:FUNDAMENTAL-STREAM)
                (STREAM (OR EXT:ANSI-STREAM
                         #+clos-streams GRAY:FUNDAMENTAL-STREAM))
                (EXT:VIRTUAL-STREAM (OR STRING-STREAM #+clos-streams GRAY:FUNDAMENTAL-STREAM))

src/tests/normal-tests/compiler.lsp

@@ -76,9 +76,13 @@
 ;;;
 ;;;     There is a problem with SUBTYPEP and type STREAM
 ;;;
+(defclass gray-stream-test (gray:fundamental-character-output-stream) ())
 (test cmp.0005.subtypep-stream
   (is (equal (multiple-value-list
               (subtypep (find-class 'gray:fundamental-stream) 'stream))
+             (list t t)))
+  (is (equal (multiple-value-list
+              (subtypep (find-class 'gray-stream-test) 'stream))
              (list t t))))
 
 ;;; Date: 09/07/2006 (Tim S)