treewide: Use pkgs/build-support/roles.bash to remove copy pasta

Also fix some setup hooks that unnecessarily used environment hooks,
which revolted in the same variable being modified too many times.

pkgs/build-support/bintools-wrapper/setup-hook.sh

@@ -11,44 +11,22 @@ set -u
 [[ -z ${crossConfig-} ]] || (( "$hostOffset" < 0 )) || return 0
 
 bintoolsWrapper_addLDVars () {
-    case $depHostOffset in
-        -1) local role='BUILD_' ;;
-        0)  local role='' ;;
-        1)  local role='TARGET_' ;;
-        *)  echo "bintools-wrapper: Error: Cannot be used with $depHostOffset-offset deps" >2;
-            return 1 ;;
-    esac
+    # See ../setup-hooks/role.bash
+    local role_post role_pre
+    getTargetRoleEnvHook
 
     if [[ -d "$1/lib64" && ! -L "$1/lib64" ]]; then
-        export NIX_${role}LDFLAGS+=" -L$1/lib64"
+        export NIX_${role_pre}LDFLAGS+=" -L$1/lib64"
     fi
 
     if [[ -d "$1/lib" ]]; then
-        export NIX_${role}LDFLAGS+=" -L$1/lib"
+        export NIX_${role_pre}LDFLAGS+=" -L$1/lib"
     fi
 }
 
-case $targetOffset in
-    -1)
-        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_BUILD=1
-        role_pre='BUILD_'
-        role_post='_FOR_BUILD'
-        ;;
-    0)
-        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_HOST=1
-        role_pre=''
-        role_post=''
-        ;;
-    1)
-        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_TARGET=1
-        role_pre='TARGET_'
-        role_post='_FOR_TARGET'
-        ;;
-    *)
-        echo "cc-wrapper: used as improper sort of dependency" >2;
-        return 1
-        ;;
-esac
+# See ../setup-hooks/role.bash
+getTargetRole
+getTargetRoleWrapper
 
 addEnvHooks "$targetOffset" bintoolsWrapper_addLDVars