perf: extend table on env startup instead of letting zend_hash_copy do it (#2272)

this can potentially save us a few internal calls to zend_hash_do_resize
while it loops over the source table (main_thread_env)

`8 -> 16 -> 32 -> 64 -> 128` becomes `8 -> target_size (rounded to power
of 2) 128`.

Author: henderkes

frankenphp.c

@@ -288,6 +288,8 @@ bool frankenphp_shutdown_dummy_request(void) {
 }
 
 void get_full_env(zval *track_vars_array) {
+  zend_hash_extend(Z_ARR_P(track_vars_array),
+                   zend_hash_num_elements(main_thread_env), 0);
   zend_hash_copy(Z_ARR_P(track_vars_array), main_thread_env, NULL);
 }
 
@@ -813,6 +815,7 @@ void frankenphp_register_server_vars(zval *track_vars_array,
                                      frankenphp_server_vars vars) {
   HashTable *ht = Z_ARRVAL_P(track_vars_array);
   zend_hash_extend(ht, vars.total_num_vars, 0);
+  zend_hash_copy(ht, main_thread_env, NULL);
 
   // update values with variable strings
 #define FRANKENPHP_REGISTER_VAR(name)                                          \
@@ -958,9 +961,7 @@ static void frankenphp_register_variables(zval *track_vars_array) {
    * $_SERVER and $_ENV should only contain values from the original
    * environment, not values added though putenv
    */
-  zend_hash_copy(Z_ARR_P(track_vars_array), main_thread_env, NULL);
-
-  /* import CGI variables from the request context in go */
+  /* import environment and CGI variables from the request context in go */
   go_register_server_variables(thread_index, track_vars_array);
 
   /* Some variables are already present in SG(request_info) */