gcc 4.7: remove now useless GNU/Hurd-related patch

pkgs/development/compilers/gcc/4.7/default.nix

@@ -60,8 +60,7 @@ let version = "4.7.2";
       # The GNAT Makefiles did not pay attention to CFLAGS_FOR_TARGET for its
       # target libraries and tools.
       ++ optional langAda ./gnat-cflags.patch
-      ++ optional langFortran ./gfortran-driving.patch
-      ++ optional (stdenv.isGNU || crossGNU) ./hurd-sigrtmin.patch;
+      ++ optional langFortran ./gfortran-driving.patch;
 
     javaEcj = fetchurl {
       # The `$(top_srcdir)/ecj.jar' file is automatically picked up at
@@ -308,7 +307,6 @@ stdenv.mkDerivation ({
     else "install";
 
   crossAttrs = {
-    patches = patches ++ [ ./hurd-sigrtmin.patch ];
     AR = "${stdenv.cross.config}-ar";
     LD = "${stdenv.cross.config}-ld";
     CC = "${stdenv.cross.config}-gcc";

pkgs/development/compilers/gcc/4.7/hurd-sigrtmin.patch

@@ -1,14 +0,0 @@
-GNU libc on GNU/Hurd doesn't define `__SIGRTMIN'.
-From <http://patch-tracker.debian.org/patch/series/view/gcc-4.6/4.6.3-1/hurd-fixes.diff>.
-
---- a/libgcc/generic-morestack.c	2011-12-19 21:14:52.000000000 +0100
-+++ b/libgcc/generic-morestack.c	2011-12-19 21:15:35.000000000 +0100
-@@ -507,7 +507,7 @@
-   sigemptyset (&__morestack_initial_sp.mask);
- 
-   sigfillset (&__morestack_fullmask);
--#ifdef __GLIBC__
-+#if defined(__GLIBC__) && defined(__SIGRTMIN)
-   /* In glibc, the first two real time signals are used by the NPTL
-      threading library.  By taking them out of the set of signals, we
-      avoiding copying the signal mask in pthread_sigmask.  More