Don't pass --target when CC/CXX contains clang

diff --git third_party/rust/cc/src/lib.rs third_party/rust/cc/src/lib.rs
index 9d133a0..273e520 100644
--- third_party/rust/cc/src/lib.rs
+++ third_party/rust/cc/src/lib.rs
@@ -2667,24 +2667,7 @@ impl Tool {
     }
 
     fn with_features(path: PathBuf, clang_driver: Option<&str>, cuda: bool) -> Self {
-        // Try to detect family of the tool from its name, falling back to Gnu.
-        let family = if let Some(fname) = path.file_name().and_then(|p| p.to_str()) {
-            if fname.contains("clang-cl") {
-                ToolFamily::Msvc { clang_cl: true }
-            } else if fname.ends_with("cl") || fname == "cl.exe" {
-                ToolFamily::Msvc { clang_cl: false }
-            } else if fname.contains("clang") {
-                match clang_driver {
-                    Some("cl") => ToolFamily::Msvc { clang_cl: true },
-                    _ => ToolFamily::Clang,
-                }
-            } else {
-                ToolFamily::Gnu
-            }
-        } else {
-            ToolFamily::Gnu
-        };
-
+        let family = ToolFamily::Gnu;
         Tool {
             path: path,
             cc_wrapper_path: None,