transpile: only consider source ranges of top-level decls

otherwise, inner decls like local variables confuse our tracking of definition bounds

Author: fw-immunant

c2rust-transpile/src/c_ast/mod.rs

@@ -309,9 +309,10 @@ impl TypedAstContext {
         };
         // Sort decls by source location so we can reason about the possibly comment-containing gaps
         // between them.
-        let mut decls_sorted = self.c_decls.clone();
-        decls_sorted.sort_by(|_k1, v1, _k2, v2| v1.begin_loc().cmp(&v2.begin_loc()));
-        for (decl_id, decl) in &decls_sorted {
+        let mut decls_sorted = self.c_decls_top.clone();
+        decls_sorted.sort_by_key(|decl| self.c_decls[decl].begin_loc());
+        for decl_id in &decls_sorted {
+            let decl = &self.c_decls[decl_id];
             let begin_loc: SrcLoc = decl.begin_loc().expect("no begin loc for top-level decl");
             let end_loc: SrcLoc = decl.end_loc().expect("no end loc for top-level decl");