gnu: gcl: Clean up inputs.

* gnu/packages/lisp.scm (gcl)[arguments]: Remove readline substitution,
correctly substitute '/bin/sh' calls.
[inputs]: Add gmp, readline.
[native-inputs]: Remove readline.

gnu/packages/lisp.scm

@@ -91,13 +91,6 @@
        #:phases (alist-cons-before
                 'configure 'pre-conf
                 (lambda _
-                  ;; Patch bug when building readline support.  This bug was
-                  ;; also observed by Debian
-                  ;; https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741819
-                  (substitute* "o/gcl_readline.d"
-                    (("rl_attempted_completion_function = \
-\\(CPPFunction \\*\\)rl_completion;")
-                      "rl_attempted_completion_function = rl_completion;"))
                   (substitute*
                       (append
                        '("pcl/impl/kcl/makefile.akcl"
@@ -107,16 +100,21 @@
                          "gcl-tk/makefile.prev"
                          "add-defs1")
                        (find-files "h" "\\.defs"))
-                    (("SHELL=/bin/(ba)?sh")
-                     (string-append "SHELL=" (which "bash")))))
+                    (("SHELL=/bin/bash")
+                     (string-append "SHELL=" (which "bash")))
+                    (("SHELL=/bin/sh")
+                     (string-append "SHELL=" (which "sh"))))
+                  #t)
                 ;; drop strip phase to make maxima build, see
                 ;; https://www.ma.utexas.edu/pipermail/maxima/2008/009769.html
                 (alist-delete 'strip
                  %standard-phases))))
+    (inputs
+     `(("gmp" ,gmp)
+       ("readline" ,readline)))
     (native-inputs
      `(("gcc" ,gcc-4.9)
        ("m4" ,m4)
-       ("readline" ,readline)
        ("texinfo" ,texinfo)
        ("texlive" ,texlive)))
     (home-page "https://www.gnu.org/software/gcl/")