Explicitly disable llvm tools for cranelift

Author: jieyouxu

compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh

@@ -38,6 +38,9 @@ local-rebuild = true
 codegen-backends = ["cranelift"]
 deny-warnings = false
 verbose-tests = false
+# Enabled by default, but cranelift does not need/want llvm tools.
+llvm_tools = false
+
 EOF
 popd