treewide: disable -Werror for llvm 7

Some of these have errors on newest llvm. It’s easiest to just add
-Wno-error in these cases.

pkgs/applications/graphics/imgcat/default.nix

@@ -22,6 +22,8 @@ stdenv.mkDerivation rec {
     sha256 = "0m83c33rzxvs0w214njql2c7q3fg06wnyijch3l2s88i7frl121f";
   };
 
+  NIX_CFLAGS_COMPILE = "-Wno-error";
+
   meta = with stdenv.lib; {
     description = "It's like cat, but for images";
     homepage = https://github.com/eddieantonio/imgcat;

pkgs/applications/science/astronomy/xplanet/default.nix

@@ -17,6 +17,8 @@ stdenv.mkDerivation rec {
     ./gcc6.patch
   ];
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=c++11-narrowing";
+
   meta = {
     description = "Renders an image of the earth or other planets into the X root window";
     homepage = http://xplanet.sourceforge.net;

pkgs/applications/science/biology/cmtk/default.nix

@@ -11,6 +11,8 @@ stdenv.mkDerivation rec {
 
   buildInputs = [cmake];
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=c++11-narrowing";
+
   meta = with stdenv.lib; {
     description     = "Computational Morphometry Toolkit ";
     longDescription = ''A software toolkit for computational morphometry of

pkgs/development/libraries/bullet/default.nix

@@ -40,6 +40,8 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=argument-outside-range";
+
   meta = with stdenv.lib; {
     description = "A professional free 3D Game Multiphysics Library";
     longDescription = ''

pkgs/development/libraries/clucene-core/2.x.nix

@@ -36,6 +36,8 @@ stdenv.mkDerivation rec {
   # /build/clucene-core-2.3.3.4/build/bin/cl_test"
   doCheck = false;
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=c++11-narrowing";
+
   meta = with stdenv.lib; {
     description = "Core library for full-featured text search engine";
     longDescription = ''

pkgs/tools/archivers/p7zip/default.nix

@@ -37,6 +37,8 @@ stdenv.mkDerivation rec {
 
   setupHook = ./setup-hook.sh;
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=c++11-narrowing";
+
   meta = {
     homepage = http://p7zip.sourceforge.net/;
     description = "A port of the 7-zip archiver";

pkgs/tools/compression/pbzip2/default.nix

@@ -17,6 +17,8 @@ stdenv.mkDerivation rec {
 
   installFlags = "PREFIX=$(out)";
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=reserved-user-defined-literal";
+
   meta = with stdenv.lib; {
     homepage = http://compression.ca/pbzip2/;
     description = "A parallel implementation of bzip2 for multi-core machines";

pkgs/tools/misc/toybox/default.nix

@@ -54,6 +54,8 @@ stdenv.mkDerivation rec {
   checkInputs = [ which ]; # used for tests with checkFlags = [ "DEBUG=true" ];
   checkTarget = "tests";
 
+  NIX_CFLAGS_COMPILE = "-Wno-error";
+
   meta = with stdenv.lib; {
     description = "Lightweight implementation of some Unix command line utilities";
     homepage = https://landley.net/toybox/;

pkgs/tools/networking/ntopng/default.nix

@@ -53,7 +53,7 @@ stdenv.mkDerivation rec {
     sed 's|LIBS += -lstdc++.6||' -i Makefile
   '';
 
-  NIX_CFLAGS_COMPILE = [ "-fpermissive" ];
+  NIX_CFLAGS_COMPILE = [ "-fpermissive" "-Wno-error=reserved-user-defined-literal" ];
 
   meta = with stdenv.lib; {
     description = "High-speed web-based traffic analysis and flow collection tool";

pkgs/tools/security/opensc/default.nix

@@ -21,6 +21,8 @@ stdenv.mkDerivation rec {
     libXt libxslt libiconv docbook_xml_dtd_412
   ] ++ stdenv.lib.optional stdenv.isDarwin Carbon;
 
+  NIX_CFLAGS_COMPILE = "-Wno-error";
+
   configureFlags = [
     "--enable-zlib"
     "--enable-readline"