Fix memory corruption in handle_map

Author: Noam Preil

assembler/directives.c

@@ -970,8 +970,8 @@ int handle_list(struct assembler_state *state, char **argv, int argc) {
 
 int handle_map(struct assembler_state *state, char **argv, int argc) {
 	// .map filename, lineno, code
-	strcpy(((source_map_t *)stack_peek(state->source_map_stack))->file_name, argv[0]);
-	add_source_map((source_map_t *)stack_peek(state->source_map_stack),
+	free(((source_map_t *)stack_peek(state->source_map_stack))->file_name);
+	((source_map_t*)stack_peek(state->source_map_stack))->file_name = strdup(argv[0]);	add_source_map((source_map_t *)stack_peek(state->source_map_stack),
 		atoi(argv[1]), argv[2], state->PC, 1); // TODO: figure out actual length
 	return 1;
 }