Merge pull request #142793 from helsinki-systems/upd/gcc8

pkgs/development/compilers/gcc/8/default.nix

···
 with builtins;
 
 let majorVersion = "8";
-    version = "${majorVersion}.4.0";
+    version = "${majorVersion}.5.0";
 
     inherit (stdenv) buildPlatform hostPlatform targetPlatform;
 
···
 
   src = fetchurl {
     url = "mirror://gcc/releases/gcc-${version}/gcc-${version}.tar.xz";
-    sha256 = "1m1d3gfix56w4aq8myazzfffkl8bqcrx4jhhapnjf7qfs596w2p3";
+    sha256 = "0l7d4m9jx124xsk6xardchgy2k5j5l2b15q322k31f0va4d8826k";
   };
 
   inherit patches;