gnu: gcj: Switch dejagnu test command.

* gnu/packages/gcc.scm (gcj)[arguments]: Switch the depreciated dejagnu
command 'absolute' for the new testing command 'file normalize'.

gnu/packages/gcc.scm

@@ -558,6 +558,13 @@ as the 'native-search-paths' field."
                  (string-append line " -Wl,-rpath=$(libdir)"))
                 (("libgcj(_bc)?_la_LDFLAGS =" ldflags _)
                  (string-append ldflags " -Wl,-rpath=$(libdir)")))))
+           (add-after
+            'unpack 'patch-testsuite
+            ;; dejagnu-1.6 removes the 'absolute' command
+            (lambda _
+              (substitute* "libjava/testsuite/lib/libjava.exp"
+                (("absolute") "file normalize"))
+              #t))
            (add-after
             'install 'install-javac-and-javap-wrappers
             (lambda _