Fixes

Author: chrisseaton

spec/ruby/optional/capi/encoding_spec.rb

@@ -485,7 +485,7 @@
       @s.rb_enc_str_asciionly_p("hello").should be_true
     end
 
-    it "returns true for a non-ASCII string" do
+    it "returns false for a non-ASCII string" do
       @s.rb_enc_str_asciionly_p("hüllo").should be_false
     end
   end

src/main/c/cext/ruby.c

@@ -4715,7 +4715,7 @@ void rb_define_virtual_variable(const char *name, VALUE (*getter)(ANYARGS), void
 }
 
 void rb_gc_register_mark_object(VALUE obj) {
-  RUBY_CEXT_INVOKE("rb_gc_register_mark_object", obj);
+  RUBY_CEXT_INVOKE_NO_WRAP("rb_gc_register_mark_object", obj);
 }
 
 ID rb_check_id(volatile VALUE *namep) {