- Detect system shaderc on BSDs

--- cargo-crates/shaderc-sys-0.8.0/build/build.rs.orig	1970-01-01 00:00:00 UTC
+++ cargo-crates/shaderc-sys-0.8.0/build/build.rs
@@ -287,10 +287,13 @@ fn main() {
             }
         } {
             match (target_os.as_str(), target_env.as_str()) {
-                ("linux", _) => {
+                ("linux", _) | ("dragonfly", _) | ("freebsd", _) | ("netbsd", _) | ("openbsd", _) => {
                     println!("cargo:rustc-link-search=native={}", search_dir_str);
                     println!("cargo:rustc-link-lib={}={}", lib_kind, lib_name);
-                    println!("cargo:rustc-link-lib=dylib=stdc++");
+                    println!("cargo:rustc-link-lib=dylib={}", match target_os.as_str() {
+                        "freebsd" | "openbsd" => "c++",
+                        _ => "stdc++",
+                    });
                     return;
                 }
                 ("windows", "msvc") => {
@@ -373,8 +376,8 @@ fn emit_std_cpp_link() {
     let target_env = env::var("CARGO_CFG_TARGET_ENV").unwrap();
 
     match (target_os.as_str(), target_env.as_str()) {
-        ("linux", _) | ("windows", "gnu") => println!("cargo:rustc-link-lib=dylib=stdc++"),
-        ("macos", _) => println!("cargo:rustc-link-lib=dylib=c++"),
+        ("linux", _) | ("dragonfly", _) | ("netbsd", _) | ("windows", "gnu") => println!("cargo:rustc-link-lib=dylib=stdc++"),
+        ("macos", _) | ("freebsd", _) | ("openbsd", _) => println!("cargo:rustc-link-lib=dylib=c++"),
         _ => {}
     }
 }
