Rename labels in `Check_Type` more descriptive

include/ruby/internal/value_type.h

@@ -337,25 +337,19 @@ static inline void
 Check_Type(VALUE v, enum ruby_value_type t)
 {
     if (RB_UNLIKELY(! RB_TYPE_P(v, t))) {
-        goto slowpath;
+        goto unexpected_type;
     }
-    else if (t != RUBY_T_DATA) {
-        goto fastpath;
-    }
-    else if (rbimpl_rtypeddata_p(v)) {
+    else if (t == RUBY_T_DATA && rbimpl_rtypeddata_p(v)) {
         /* The intention itself is not necessarily clear to me, but at least it
          * is  intentional   to  rule   out  typed   data  here.    See  commit
          * a7c32bf81d3391cfb78cfda278f469717d0fb794. */
-        goto slowpath;
+        goto unexpected_type;
     }
     else {
-        goto fastpath;
+        return;
     }
 
-  fastpath:
-    return;
-
-  slowpath: /* <- :TODO: mark this label as cold. */
+  unexpected_type:
     rb_unexpected_type(v, t);
 }