[ruby/prism] Fix not binding power in endless methods [Backport #21097]

Change rescue modifier binding power from PM_BINDING_POWER_COMPOSITION
to PM_BINDING_POWER_MATCH + 1, so that `x = a rescue b in c` is parsed
as `(x = (a rescue b)) in c` and `def f = a rescue b in c` is parsed
as `(def f = (a rescue b)) in c`.

ruby/prism@7e797f59ae

Author: k0kubun

prism/prism.c

@@ -18956,7 +18956,7 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
                     context_push(parser, PM_CONTEXT_RESCUE_MODIFIER);
 
                     pm_token_t rescue_keyword = parser->previous;
-                    pm_node_t *value = parse_expression(parser, pm_binding_powers[PM_TOKEN_KEYWORD_RESCUE_MODIFIER].right, false, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
+                    pm_node_t *value = parse_expression(parser, PM_BINDING_POWER_MATCH + 1, false, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
                     context_pop(parser);
 
                     statement = UP(pm_rescue_modifier_node_create(parser, statement, &rescue_keyword, value));
@@ -20253,7 +20253,7 @@ parse_assignment_value(pm_parser_t *parser, pm_binding_power_t previous_binding_
         pm_token_t rescue = parser->current;
         parser_lex(parser);
 
-        pm_node_t *right = parse_expression(parser, pm_binding_powers[PM_TOKEN_KEYWORD_RESCUE_MODIFIER].right, false, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
+        pm_node_t *right = parse_expression(parser, PM_BINDING_POWER_MATCH + 1, false, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
         context_pop(parser);
 
         return UP(pm_rescue_modifier_node_create(parser, value, &rescue, right));
@@ -20359,7 +20359,7 @@ parse_assignment_values(pm_parser_t *parser, pm_binding_power_t previous_binding
             }
         }
 
-        pm_node_t *right = parse_expression(parser, pm_binding_powers[PM_TOKEN_KEYWORD_RESCUE_MODIFIER].right, accepts_command_call_inner, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
+        pm_node_t *right = parse_expression(parser, PM_BINDING_POWER_MATCH + 1, accepts_command_call_inner, false, PM_ERR_RESCUE_MODIFIER_VALUE, (uint16_t) (depth + 1));
         context_pop(parser);
 
         return UP(pm_rescue_modifier_node_create(parser, value, &rescue, right));