gcc: Add configurePlatforms exception for Arm 32

...just as we did for binutils. When the underlying issue is resolved
(probably with a configure script patch or lib/systems/parse.nix
change), this should be reverted.

pkgs/development/compilers/gcc/7/default.nix

@@ -328,7 +328,12 @@ stdenv.mkDerivation ({
   dontDisableStatic = true;
 
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
-  configurePlatforms = [ "build" "host" ] ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+  configurePlatforms =
+    # TODO(@Ericson2314): Figure out what's going wrong with Arm
+    if hostPlatform == targetPlatform && targetPlatform.isArm32
+    then []
+    else [ "build" "host" ] ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+
   configureFlags = "
     ${if hostPlatform.isSunOS then
       " --enable-long-long --enable-libssp --enable-threads=posix --disable-nls --enable-__cxa_atexit " +