constify again.

Same as last commit, make some fields `const`.

include/ruby/ruby.h:
* Rasic::klass
* RArray::heap::aux::shared_root
* RRegexp::src
internal.h:
* rb_classext_struct::origin_, redefined_class
* vm_svar::cref_or_me, lastline, backref, others
* vm_throw_data::throw_obj
* vm_ifunc::data
* MEMO::v1, v2, u3::value

While modifying this patch, I found write-barrier miss on
rb_classext_struct::redefined_class.

Also vm_throw_data::throw_state is only `int` so change the type.

1 files changed, 1 insertions, 1 deletions

diff --git a/class.c b/class.c
index 7922df56b2..a8d21f9443 100644
--- a/class.c
+++ b/class.c
@@ -176,7 +176,7 @@ class_alloc(VALUE flags, VALUE klass)
      */
     RCLASS_SET_ORIGIN((VALUE)obj, (VALUE)obj);
     RCLASS_SERIAL(obj) = rb_next_class_serial();
-    RCLASS_REFINED_CLASS(obj) = Qnil;
+    RB_OBJ_WRITE(obj, &RCLASS_REFINED_CLASS(obj), Qnil);
     RCLASS_EXT(obj)->allocator = 0;
 
     return (VALUE)obj;