Add const modifier for zend_extension members

Closes GH-6462.

Author: huanghantao

Zend/zend_extensions.h

@@ -75,11 +75,11 @@ typedef size_t (*op_array_persist_calc_func_t)(zend_op_array *op_array);
 typedef size_t (*op_array_persist_func_t)(zend_op_array *op_array, void *mem);
 
 struct _zend_extension {
-	char *name;
-	char *version;
-	char *author;
-	char *URL;
-	char *copyright;
+	const char *name;
+	const char *version;
+	const char *author;
+	const char *URL;
+	const char *copyright;
 
 	startup_func_t startup;
 	shutdown_func_t shutdown;

sapi/phpdbg/phpdbg_prompt.c

@@ -1227,7 +1227,7 @@ static void add_zendext_info(zend_extension *ext) /* {{{ */ {
 /* }}} */
 
 #ifdef HAVE_LIBDL
-PHPDBG_API const char *phpdbg_load_module_or_extension(char **path, char **name) /* {{{ */ {
+PHPDBG_API const char *phpdbg_load_module_or_extension(char **path, const char **name) /* {{{ */ {
 	DL_HANDLE handle;
 	char *extension_dir;
 
@@ -1325,7 +1325,7 @@ PHPDBG_API const char *phpdbg_load_module_or_extension(char **path, char **name)
 		}
 
 		module_entry = get_module();
-		*name = (char *) module_entry->name;
+		*name = module_entry->name;
 
 		if (strcmp(ZEND_EXTENSION_BUILD_ID, module_entry->build_id)) {
 			phpdbg_error("dl", "type=\"wrongbuild\" module=\"%s\" buildneeded=\"%s\" buildinstalled=\"%s\"",  "%s was built with configuration %s, whereas running engine is %s", module_entry->name, module_entry->build_id, ZEND_EXTENSION_BUILD_ID);
@@ -1371,8 +1371,8 @@ PHPDBG_API const char *phpdbg_load_module_or_extension(char **path, char **name)
 
 PHPDBG_COMMAND(dl) /* {{{ */
 {
-	const char *type;
-	char *name, *path;
+	const char *type, *name;
+	char *path;
 
 	if (!param || param->type == EMPTY_PARAM) {
 		phpdbg_notice("dl", "extensiontype=\"Zend extension\"", "Zend extensions");
@@ -1388,7 +1388,6 @@ PHPDBG_COMMAND(dl) /* {{{ */
 			phpdbg_activate_err_buf(1);
 			if ((type = phpdbg_load_module_or_extension(&path, &name)) == NULL) {
 				phpdbg_error("dl", "path=\"%s\" %b", "Could not load %s, not found or invalid zend extension / module: %b", path);
-				efree(name);
 			} else {
 				phpdbg_notice("dl", "extensiontype=\"%s\" name=\"%s\" path=\"%s\"", "Successfully loaded the %s %s at path %s", type, name, path);
 			}