faust2: fix build with llvm 5.0.2 (#40672)

build was broken by  llvm: 5.0.1 -> 5.0.2 (#39979)

(cherry picked from commit a16c31244b)

pkgs/applications/audio/faust/faust2.nix

@@ -73,6 +73,13 @@ let
       sed '52iLLVM_VERSION=${stdenv.lib.getVersion llvm}' -i compiler/Makefile.unix
     '';
 
+    postPatch = ''
+      # fix build with llvm 5.0.2 by adding it to the list of known versions
+      # TODO: check if still needed on next update
+      substituteInPlace compiler/Makefile.unix \
+        --replace "5.0.0 5.0.1" "5.0.0 5.0.1 5.0.2"
+    '';
+
     # Remove most faust2appl scripts since they won't run properly
     # without additional paths setup. See faust.wrap,
     # faust.wrapWithBuildEnv.
@@ -193,6 +200,7 @@ let
 
       propagatedBuildInputs = [ faust ] ++ propagatedBuildInputs;
 
+
       postFixup = ''
 
         # export parts of the build environment