treewide: add targetPrefix to hardcoded references to CC=cc

pkgs/tools/misc/convbin/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
     sha256 = "0n502zj8igm583kbfvyv7zhd97vb71jac41ncb9jr2yz2v5ir8j9";
   };
 
-  makeFlags = [ "CC=cc" ];
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
 
   checkPhase = ''
     pushd test

pkgs/tools/misc/convfont/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
     sha256 = "1lj24yq5gj9hxhy1srk73521q95zyqzkws0q4v271hf5wmqaxa2f";
   };
 
-  makeFlags = [ "CC=cc" ];
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
 
   installPhase = ''
     install -Dm755 convfont $out/bin/convfont

pkgs/tools/misc/convimg/default.nix

@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
     fetchSubmodules = true;
   };
 
-  makeFlags = [ "CC=cc" ];
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
 
   checkPhase = ''
     pushd test

pkgs/tools/misc/moreutils/default.nix

@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
 
   propagatedBuildInputs = with perlPackages; [ perl IPCRun TimeDate TimeDuration ];
 
-  buildFlags = [ "CC=cc" ];
+  buildFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
   installFlags = [ "PREFIX=$(out)" ];
 
   postInstall = ''

pkgs/tools/misc/tldr/default.nix

@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ curl libzip ];
   nativeBuildInputs = [ pkg-config ];
 
-  makeFlags = ["CC=cc" "LD=cc" "CFLAGS="];
+  makeFlags = ["CC=${stdenv.cc.targetPrefix}cc" "LD=${stdenv.cc.targetPrefix}cc" "CFLAGS="];
 
   installFlags = [ "PREFIX=$(out)" ];
 

pkgs/tools/misc/unclutter/default.nix

@@ -9,7 +9,7 @@ stdenv.mkDerivation {
 
   buildInputs = [xlibsWrapper];
 
-  buildFlags = [ "CC=cc" ];
+  buildFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
 
   installPhase = ''
     mkdir -pv "$out/bin"