Prohibit array changes by "a"/"*" specifier of `mrb_get_args()`

The "a"/"*" specifier of the `mrb_get_args()` function will now return `const mrb_value *`.
This is because it is difficult for the caller to check if it is an array object and write-barrier if necessary.
And it requires calling `mrb_ary_modify()` on the unmodified array object, which is also difficult (this is similar to #5087).

1 files changed, 2 insertions, 1 deletions

diff --git a/src/vm.c b/src/vm.c
index d1f4660be..bcb78c0c9 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -552,7 +552,8 @@ mrb_value
 mrb_f_send(mrb_state *mrb, mrb_value self)
 {
   mrb_sym name;
-  mrb_value block, *argv, *regs;
+  mrb_value block, *regs;
+  const mrb_value *argv;
   mrb_int argc, i, len;
   mrb_method_t m;
   struct RClass *c;