#### Before this patch:

  ```terminal
  $ bin/mruby -v -e ':"#{1}"; ["#{2}": 0]'
  mruby 2.0.1 (2019-04-04)
  00001 NODE_SCOPE:
  00001   NODE_BEGIN:
  00001     node type: 83 (0x53)
  00001     NODE_ARRAY:
  00001       NODE_KW_HASH:
  00001         key:
  00001           node type: 83 (0x53)
  00001         value:
  00001           NODE_INT 0 base 10
  (snip)
  ```

#### After this patch:

  ```terminal
  $ bin/mruby -v -e ':"#{1}"; ["#{2}": 0]'
  mruby 2.0.1 (2019-04-04)
  00001 NODE_SCOPE:
  00001   NODE_BEGIN:
  00001     NODE_DSYM:
  00001       NODE_DSTR:
  00001         NODE_STR "" len 0
  00001         NODE_BEGIN:
  00001           NODE_INT 1 base 10
  00001         NODE_STR "" len 0
  00001     NODE_ARRAY:
  00001       NODE_KW_HASH:
  00001         key:
  00001           NODE_DSYM:
  00001             NODE_DSTR:
  00001               NODE_STR "" len 0
  00001               NODE_BEGIN:
  00001                 NODE_INT 2 base 10
  00001               NODE_STR "" len 0
  00001         value:
  00001           NODE_INT 0 base 10
  (snip)
  ```

Remove unnecessary type `mrb_hash_value`

The type `mrb_hash_value` is no longer used by the segmented list
implementation (ref e8dcfe17 and e65d4264).

Print missing `:` before newline in `mrb_parser_dump`

Allow rethrowing `MRB_TT_BREAK`

Restore GC arena frequently

Remove unnecessary assignments

Add an annotation about the return value

The return value from `mrb_delete_key` needs to be protected from GC in
some cases.

Remove unused node type in `codegen()`

Simplify arguments check in `String#rindex`

Also fix document about type of the first argument.

Use type predicate macros instead of `mrb_type` if possible

For efficiency with `MRB_WORD_BOXING` (implement type predicate macros for
all `enum mrb_vtype`).

The following two may be different:
* `%d` for `int`
* `%i` for `mrb_int`

Use inttypes for `snprintf()`

Keep the type of `posarg` consistent

Remove `MRB_TT_HAS_BASIC` macro

Fix `MRB_WITHOUT_FLOAT` reversal; fix #4598

Add "fall through"

* mrb_sym2name -> mrb_sym_name
* mrb_sym2name_len -> mrb_sym_name_len
* mrb_sym2str -> mrb_sym_str

Match the type with the caller and related functions.

The value of `MRB_TT_HAS_BASIC` is meaningless because `MRB_TT_HAS_BASIC` is
no longer used with `MRB_WORD_BOXING` at b2c3d88f.

`Exception#initialize` should not allow two or more arguments

Fix `Fixnum` overflow test in `Integer#<<` test

- Skip when `MRB_WITHOUT_FLOAT` is defined.
- Make `Fixnum` overflow even when `MRB_INT64` is defined.

Implement all type predicate macros for `MRB_WORD_BOXING`