Remove unused _get_zval_ptr_cv_BP_VAR_UNSET function

To fix the macos -Werror build.

Author: nikic

Zend/zend_execute.c

@@ -364,16 +364,6 @@ static zend_always_inline zval *_get_zval_ptr_cv_deref_BP_VAR_R(uint32_t var EXE
 	return ret;
 }
 
-static zend_always_inline zval *_get_zval_ptr_cv_BP_VAR_UNSET(uint32_t var EXECUTE_DATA_DC)
-{
-	zval *ret = EX_VAR(var);
-
-	if (UNEXPECTED(Z_TYPE_P(ret) == IS_UNDEF)) {
-		return zval_undefined_cv(var EXECUTE_DATA_CC);
-	}
-	return ret;
-}
-
 static zend_always_inline zval *_get_zval_ptr_cv_BP_VAR_IS(uint32_t var EXECUTE_DATA_DC)
 {
 	zval *ret = EX_VAR(var);