Both bindgen and clang use the same feature in

the same specific way; unify them

Cargo.toml

@@ -20,12 +20,15 @@ repository = "https://github.com/extendr/libR-sys"
 
 [build-dependencies]
 bindgen = { version = "0.69.1", optional = true, features = ["experimental"] }
-clang = { version = "2", optional = true, features = ["runtime", "clang_3_7"] }
+clang = { version = "2", optional = true, features = ["clang_3_7"] }
 
 [features]
+default = ["runtime"]
 # By default, we use pre-computed bindings that ship with the library. This may fail!
 # Turn on the 'use-bindgen' feature to generate bindings on the fly for your platform.
 use-bindgen = ["bindgen", "clang"]
+
+runtime = ["clang/runtime", "bindgen/runtime"]
 # Enables generation of layout-tests in bindgen
 layout_tests = []