Debug info: sort by generated-code offset to avoid gimli panic.

This issue was found while fuzzing the new backend (bytecodealliance#2453); I suspect
that it arises with the new backend because we can sink instructions
(e.g. loads or extends) in more interesting ways than before, but I'm
not entirely sure.

Test coverage will be via the fuzz corpus once bytecodealliance#2453 lands.

crates/debug/src/transform/address_transform.rs

@@ -206,6 +206,7 @@ fn build_function_addr_map(
                 wasm: offset,
             });
         }
+        fn_map.sort_by_key(|entry| entry.generated);
 
         if cfg!(debug) {
             // fn_map is sorted by the generated field -- see FunctionAddressMap::instructions.