#### Before this patch:
```console
$ bin/mruby rb -e '_0=:l; p ->{_0}.()'
-e:1:13: _0 is not available
-e:1:13: syntax error, unexpected $end, expecting '}'
```
#### After this patch (same as Ruby):
```console
$ bin/mruby rb -e '_0=:l; p ->{_0}.()'
:l
```
If `#methods` traverse the super class, it includes the methods that
were does `undef` in the subclass.
Before patched:
```terminal
% bin/mruby -e 'p Module.instance_methods - Class.instance_methods'
[]
```
After patched:
```terminal
% bin/mruby -e 'p Module.instance_methods - Class.instance_methods'
[:append_features, :extend_object]
```
Consecutive `_` is not allowed as a numeric expression:
1_2__3 #=> SyntaxError
Float("1_2__3") #=> ArgumentError
Integer("1_2__3") #=> ArgumentError
"1_2__3".to_i #=> 12
But `String#to_f` accept it, so I fixed the issue.
Before this patch:
"1_2__3".to_f #=> 123
After this patch:
"1_2__3".to_f #=> 12
Silence the following warnings:
```
/mruby/mrbgems/mruby-time/src/time.c:871:15: warning: result of comparison of constant 9223372036854775807 with expression of type 'time_t' (aka 'long') is always false [-Wtautological-constant-out-of-range-compare]
if (tm->sec > MRB_INT_MAX || tm->sec < MRB_INT_MIN) {
~~~~~~~ ^ ~~~~~~~~~~~
/mruby/mrbgems/mruby-time/src/time.c:871:40: warning: result of comparison of constant -9223372036854775808 with expression of type 'time_t' (aka 'long') is always false [-Wtautological-constant-out-of-range-compare]
if (tm->sec > MRB_INT_MAX || tm->sec < MRB_INT_MIN) {
~~~~~~~ ^ ~~~~~~~~~~~
/mruby/mrbgems/mruby-time/src/time.c:887:16: warning: result of comparison of constant 9223372036854775807 with expression of type 'time_t' (aka 'long') is always false [-Wtautological-constant-out-of-range-compare]
if (tm->usec > MRB_INT_MAX || tm->usec < MRB_INT_MIN) {
~~~~~~~~ ^ ~~~~~~~~~~~
/mruby/mrbgems/mruby-time/src/time.c:887:42: warning: result of comparison of constant -9223372036854775808 with expression of type 'time_t' (aka 'long') is always false [-Wtautological-constant-out-of-range-compare]
if (tm->usec > MRB_INT_MAX || tm->usec < MRB_INT_MIN) {
~~~~~~~~ ^ ~~~~~~~~~~~
```
Silence the following warning:
```
/mruby/mrbgems/mruby-time/src/time.c:258:60: warning: result of comparison of constant -9223372036854775808 with expression of type 'mrb_int' (aka 'int') is always false [-Wtautological-constant-out-of-range-compare]
if ((mrb_time_int)i > MRB_TIME_MAX || MRB_TIME_MIN > i) {
~~~~~~~~~~~~ ^ ~
```
#### Before this patch:
```
$ bin/mruby -e 'p ARGV' a b
["bin/mruby", "-e", "p ARGV", "a", "b"]
```
#### After this patch:
```
$ bin/mruby -e 'p ARGV' a b
["a", "b"]
```
take-cheeze