Temporarily override bindgen path

Depend on rust-lang/rust-bindgen#1793 for `func_macro` support.

Author: kulp

Cargo.toml

@@ -15,10 +15,13 @@ lazy_static = "1.4.0"
 
 [build-dependencies]
 attohttpc = { version = "0.15", default-features = false }
-bindgen = "0.53"
+bindgen = "*"
 cc = "1.0"
 flate2 = "1.0"
 tar = "0.4"
 
 [dev-dependencies]
 libc = "0.2"
+
+[patch.crates-io]
+bindgen = { git = "https://github.com/kulp/rust-bindgen", branch = "function-macros" }