Eliminate false-positive dead-code warnings

src/popen.rs

@@ -71,7 +71,11 @@ pub struct Popen {
 #[derive(Debug)]
 enum ChildState {
     Preparing, // only during construction
-    Running { pid: u32, ext: os::ExtChildState },
+    Running {
+        pid: u32,
+        #[allow(dead_code)]
+        ext: os::ExtChildState,
+    },
     Finished(ExitStatus),
 }
 

src/posix.rs

@@ -65,6 +65,7 @@ fn os_to_cstring(s: &OsStr) -> Result<CString> {
 struct CVec {
     // Individual C strings.  Each element self.ptrs[i] points to the
     // data of self.strings[i].as_bytes_with_nul().as_ptr().
+    #[allow(dead_code)]
     strings: Vec<CString>,
 
     // nullptr-terminated vector of pointers to data inside