Re-adding LazyConfig::is_init for use in cwd changing code

Author: compenguy

src/bin/cargo/cli.rs

@@ -497,6 +497,13 @@ impl LazyConfig {
         Self { config: None }
     }
 
+    /// Check whether the config is loaded
+    ///
+    /// This is useful for asserts in case the environment needs to be setup before loading
+    pub fn is_init(&self) -> bool {
+        self.config.is_some()
+    }
+
     /// Get the config, loading it if needed
     ///
     /// On error, the process is terminated