Do not use -- for cuda

Signed-off-by: Jiahao XU <[email protected]>

src/lib.rs

@@ -701,10 +701,13 @@ impl Build {
         if compiler.family.verbose_stderr() {
             compiler.remove_arg("-v".into());
         }
-        if compiler.is_like_clang() {
-            // Avoid reporting that the arg is unsupported just because the
-            // compiler complains that it wasn't used.
-            compiler.push_cc_arg("-Wno-unused-command-line-argument".into());
+
+        if compiler.supports_path_delimiter() && !is_assembler_msvc {
+            // #513: For `clang-cl`, separate flags/options from the input file.
+            // When cross-compiling macOS -> Windows, this avoids interpreting
+            // common `/Users/...` paths as the `/U` flag and triggering
+            // `-Wslash-u-filename` warning.
+            cmd.arg("--");
         }
 
         let mut cmd = compiler.to_command();

src/tool.rs

@@ -426,7 +426,7 @@ impl Tool {
         matches!(
             self.family,
             ToolFamily::Clang { .. } | ToolFamily::Msvc { clang_cl: true }
-        )
+        ) && !self.cuda
     }
 }