mpfr: only use 3.1.2 and drop 3.1.1

I tried some packages, all seem to compile fine.

pkgs/development/libraries/mpfr/3.1.2.nix

@@ -1,51 +0,0 @@
-
-{stdenv, fetchurl, gmp}:
-
-stdenv.mkDerivation (rec {
-  name = "mpfr-3.1.2";
-
-  src = fetchurl {
-    url = "mirror://gnu/mpfr/${name}.tar.bz2";
-    sha256 = "0sqvpfkzamxdr87anzakf9dhkfh15lfmm5bsqajk02h1mxh3zivr";
-  };
-
-  buildInputs = [ gmp ];
-
-  doCheck = true;
-
-  enableParallelBuilding = true;
-
-  meta = {
-    homepage = http://www.mpfr.org/;
-    description = "GNU MPFR, a library for multiple-precision floating-point arithmetic";
-
-    longDescription = ''
-      The GNU MPFR library is a C library for multiple-precision
-      floating-point computations with correct rounding.  MPFR is
-      based on the GMP multiple-precision library.
-
-      The main goal of MPFR is to provide a library for
-      multiple-precision floating-point computation which is both
-      efficient and has a well-defined semantics.  It copies the good
-      ideas from the ANSI/IEEE-754 standard for double-precision
-      floating-point arithmetic (53-bit mantissa).
-    '';
-
-    license = "LGPLv2+";
-
-    maintainers = [ stdenv.lib.maintainers.ludo ];
-    platforms = stdenv.lib.platforms.all;
-  };
-}
-
-//
-
-(stdenv.lib.optionalAttrs stdenv.isFreeBSD {
-   /* Work around a FreeBSD bug that otherwise leads to segfaults in
-      the test suite:
-        http://hydra.bordeaux.inria.fr/build/34862
-        http://websympa.loria.fr/wwsympa/arc/mpfr/2011-10/msg00015.html
-        http://www.freebsd.org/cgi/query-pr.cgi?pr=161344
-    */
-   configureFlags = [ "--disable-thread-safe" ];
- }))

pkgs/development/libraries/mpfr/default.nix

@@ -1,15 +1,24 @@
-{stdenv, fetchurl, gmp}:
+{ stdenv, fetchurl, gmp }:
 
 stdenv.mkDerivation rec {
-  name = "mpfr-3.1.1";
+  name = "mpfr-3.1.2";
 
   src = fetchurl {
     url = "mirror://gnu/mpfr/${name}.tar.bz2";
-    sha256 = "1zfmmk4p26b67qpmh787p3dfxa71yd9mi02c4q45yf687pqw6rkv";
+    sha256 = "0sqvpfkzamxdr87anzakf9dhkfh15lfmm5bsqajk02h1mxh3zivr";
   };
 
   buildInputs = [ gmp ];
 
+  configureFlags =
+    /* Work around a FreeBSD bug that otherwise leads to segfaults in the test suite:
+          http://hydra.bordeaux.inria.fr/build/34862
+          http://websympa.loria.fr/wwsympa/arc/mpfr/2011-10/msg00015.html
+          http://www.freebsd.org/cgi/query-pr.cgi?pr=161344
+      */
+    stdenv.lib.optional (stdenv.isSunOS or stdenv.isFreeBSD) "--disable-thread-safe" ++
+    stdenv.lib.optional stdenv.is64bit "--with-pic";
+
   doCheck = true;
 
   enableParallelBuilding = true;
@@ -35,14 +44,5 @@ stdenv.mkDerivation rec {
     maintainers = [ stdenv.lib.maintainers.ludo ];
     platforms = stdenv.lib.platforms.all;
   };
-
-  configureFlags =
-    /* Work around a FreeBSD bug that otherwise leads to segfaults in
-        the test suite:
-          http://hydra.bordeaux.inria.fr/build/34862
-          http://websympa.loria.fr/wwsympa/arc/mpfr/2011-10/msg00015.html
-          http://www.freebsd.org/cgi/query-pr.cgi?pr=161344
-      */
-    stdenv.lib.optional (stdenv.isSunOS or stdenv.isFreeBSD) "--disable-thread-safe" ++
-    stdenv.lib.optional stdenv.is64bit "--with-pic";
 }
+

pkgs/top-level/all-packages.nix

@@ -4018,16 +4018,18 @@ let
   gmm = callPackage ../development/libraries/gmm { };
 
   gmp = gmp5;
+  gmp5 = gmp51;
 
   gmpxx = appendToName "with-cxx" (gmp.override { cxx = true; });
 
   # The GHC bootstrap binaries link against libgmp.so.3, which is in GMP 4.x.
   gmp4 = callPackage ../development/libraries/gmp/4.3.2.nix { };
 
-  gmp5 = gmp51;
-
   gmp51 = callPackage ../development/libraries/gmp/5.1.x.nix { };
 
+  #GMP ex-satellite, so better keep it near gmp
+  mpfr = callPackage ../development/libraries/mpfr/default.nix { };
+
   gobjectIntrospection = callPackage ../development/libraries/gobject-introspection { };
 
   goffice = callPackage ../development/libraries/goffice {
@@ -4047,10 +4049,6 @@ let
 
   gperftools = callPackage ../development/libraries/gperftools { };
 
-  #GMP ex-satellite, so better keep it near gmp
-  mpfr = callPackage ../development/libraries/mpfr { };
-  mpfr_3_1_2 = callPackage ../development/libraries/mpfr/3.1.2.nix { };
-
   gst_all = {
     inherit (pkgs) gstreamer gnonlin gst_python qt_gstreamer;
     gstPluginsBase = pkgs.gst_plugins_base;