share :cause variable

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63431 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

error.c

@@ -886,7 +886,9 @@ VALUE rb_eSystemCallError;
 VALUE rb_mErrno;
 static VALUE rb_eNOERROR;
 
-static ID id_cause, id_message, id_backtrace;
+ID ruby_static_id_cause;
+#define id_cause ruby_static_id_cause
+static ID id_message, id_backtrace;
 static ID id_name, id_key, id_args, id_Errno, id_errno, id_i_path;
 static ID id_receiver, id_recv, id_iseq, id_local_variables;
 static ID id_private_call_p, id_top, id_bottom;

eval.c

@@ -30,7 +30,8 @@ VALUE rb_eLocalJumpError;
 VALUE rb_eSysStackError;
 
 ID ruby_static_id_signo, ruby_static_id_status;
-static ID id_cause;
+extern ID ruby_static_id_cause;
+#define id_cause ruby_static_id_cause
 
 #define exception_error GET_VM()->special_exceptions[ruby_error_reenter]
 
@@ -1950,5 +1951,4 @@ Init_eval(void)
 
     id_signo = rb_intern_const("signo");
     id_status = rb_intern_const("status");
-    id_cause = rb_intern_const("cause");
 }