When p->locals->car is not NULL and p->locals->car->car is NULL,
local_add_f dose not append sym to p->locals->car->car.
This commit change to append sym to p->locals->car->car.
This will close #2333.

Fix typos in gc

Remove space.

Improve `Struct#[]=`.

Fix invalid array initialize for VS2012

fix indent.

Replace assert_true with assert_equal.

Exception#exception fix test

Fix assert_equal argument order in test/t/proc.rb

Use `assert_*` method instead of using result value in fiber test.

Use `assert_kind_of` instead in `Proc#inspect` test.

fix typo.

Exception.exception is not call Exception#exception.
Test for Exception#exception should call Exception#exception method.

Use `do ... end` for test block.

Should not call inherited method when class nothing

when class nothing

Update C++ extensions in build instruction document.

Class.new do not call `class_eval'

Module#initialize set created object for block argument

Change range_check before mrb_obj_alloc.