Emit a warning when the case of the import file differ from the case …

…of the file that was imported

Fixes #4265

Not easy to test since this is platform dependent

internal/compiler/typeloader.rs

@@ -1052,7 +1052,25 @@ impl TypeLoader {
             .tl
             .resolve_import_path(import_token.as_ref(), file_to_import)
         {
-            Some(x) => x,
+            Some(x) => {
+                if let Some(file_name) = x.0.file_name().and_then(|f| f.to_str()) {
+                    let len = file_to_import.len();
+                    if !file_to_import.ends_with(file_name)
+                        && len >= file_name.len()
+                        && file_name.eq_ignore_ascii_case(
+                            &file_to_import.get(len - file_name.len()..).unwrap_or(""),
+                        )
+                    {
+                        if import_token.as_ref().and_then(|x| x.source_file()).is_some() {
+                            borrowed_state.diag.push_warning(
+                                format!("Loading \"{file_to_import}\" resolved to a file named \"{file_name}\" with different casing. This behavior is not cross platform. Rename the file, or edit the import to use the same casing"),
+                                &import_token,
+                            );
+                        }
+                    }
+                }
+                x
+            }
             None => {
                 let import_path = crate::pathutils::clean_path(Path::new(file_to_import));
                 if import_path.exists() {