php: Throw exceptions instead of using errors

Parameter type errors and some other cases in SWIG-generated wrappers
now throw a PHP exception, which is how PHP's native parameter handling
deals with similar situations.

See #2014, but not closing yet as there may be more cases to convert.

Lib/php/typemaps.i

@@ -276,7 +276,8 @@ INT_TYPEMAP(unsigned long long);
     /* So... we didn't get a ref or ptr, but we'll accept NULL by reference */
     if (!(Z_ISREF($input) && Z_ISNULL_P(Z_REFVAL($input)))) {
       /* wasn't a pre/ref/thing, OR anything like an int thing */
-      SWIG_PHP_Error(E_ERROR, "Type error in argument $arg of $symname.");
+      zend_type_error("Expected reference or NULL for argument $arg of $symname");
+      SWIG_FAIL;
     }
   }
   force=0;