gnu: lua-lpeg: Avoid code repetition.

* gnu/packages/lua.scm (make-lua-lpeg): New procedure.
(lua-lpeg, lua5.2-lpeg): Call make-lua-lpeg.

gnu/packages/lua.scm

@@ -356,9 +356,9 @@ based libraries.  It allows using GObject-based libraries directly from Lua.
 Notable examples are GTK+, GStreamer and Webkit.")
     (license license:expat)))
 
-(define-public lua-lpeg
+(define (make-lua-lpeg name lua)
   (package
-    (name "lua-lpeg")
+    (name name)
     (version "1.0.1")
     (source (origin
               (method url-fetch)
@@ -390,29 +390,11 @@ Grammars (PEGs).")
     (home-page "http://www.inf.puc-rio.br/~roberto/lpeg")
     (license license:expat)))
 
+(define-public lua-lpeg
+  (make-lua-lpeg "lua-lpeg" lua))
+
 (define-public lua5.2-lpeg
-  (package (inherit lua-lpeg)
-    (name "lua5.2-lpeg")
-    ;; XXX: The arguments field is almost an exact copy of the field in
-    ;; "lua-lpeg", except for the version string, which was derived from "lua"
-    ;; and now is taken from "lua-5.2".  See this discussion for context:
-    ;; http://lists.gnu.org/archive/html/guix-devel/2017-01/msg02048.html
-    (arguments
-     `(#:phases
-       (modify-phases %standard-phases
-         (delete 'configure)
-         ;; `make install` isn't available, so we have to do it manually
-         (replace 'install
-           (lambda* (#:key outputs #:allow-other-keys)
-             (let ((out (assoc-ref outputs "out"))
-                   (lua-version ,(version-major+minor (package-version lua-5.2))))
-               (install-file "lpeg.so"
-                             (string-append out "/lib/lua/" lua-version))
-               (install-file "re.lua"
-                             (string-append out "/share/lua/" lua-version))
-               #t))))
-       #:test-target "test"))
-    (inputs `(("lua", lua-5.2)))))
+  (make-lua-lpeg "lua5.2-lpeg" lua-5.2))
 
 ;; Lua 5.3 is not supported.
 (define (make-lua-bitop name lua)