Fix rust-invoked build of c/cpp sources under FreeBSD

Due to an upstream issue with cc-rs [0], the rust-generated C++ interface would
fail to compile. A PR has been opened to patch the issue upstream [1], but in
the meantime `Cargo.toml` has been patched to use a fork of cc-rs with the
relevant fixes.

[0]: rust-lang/cc-rs#463
[1]: rust-lang/cc-rs#785

fish-rust/Cargo.toml

@@ -34,12 +34,19 @@ default = ["fish-ffi-tests"]
 fish-ffi-tests = ["inventory"]
 
 [patch.crates-io]
+cc = { git = "https://github.com/mqudsi/cc-rs", branch = "fish" }
 cxx = { git = "https://github.com/ridiculousfish/cxx", branch = "fish" }
 cxx-gen = { git = "https://github.com/ridiculousfish/cxx", branch = "fish" }
 autocxx = { git = "https://github.com/ridiculousfish/autocxx", branch = "fish" }
 autocxx-build = { git = "https://github.com/ridiculousfish/autocxx", branch = "fish" }
 autocxx-bindgen = { git = "https://github.com/ridiculousfish/autocxx-bindgen", branch = "fish" }
 
+[patch.'https://github.com/ridiculousfish/cxx']
+cc = { git = "https://github.com/mqudsi/cc-rs", branch = "fish" }
+
+[patch.'https://github.com/ridiculousfish/autocxx']
+cc = { git = "https://github.com/mqudsi/cc-rs", branch = "fish" }
+
 #cxx = { path = "../../cxx" }
 #cxx-gen = { path="../../cxx/gen/lib" }
 #autocxx = { path = "../../autocxx" }