Fix parameters when noname rest

According to CRuby [Feature#12746]

Modify to get constant of parent module in singleton class; fix #3568

The resulting behavior is different from CRuby, but modifying
hash key afterwards is undefined behavior in ISO spec.

Modify class variable definition in singleton class; fix #3539

Fix Enumerator#each_with_index with block

In previous version,

```
a = [3, 2, 1]
e = a.each
e.sort_by(&:to_i) # => []
```

In this version,

```
a = [3, 2, 1]
e = a.each
e.sort_by(&:to_i) # => [1, 2, 3]
```

Should raise FloatDomainError

Renumber hash keys during dup since there may be duplicates.

Set proper class to subclass of Array

More compatibility to CRuby.

Implement Array#slice!

Fix infinity loop ref #3546

And some cases should raise FloatDomainError

Fix lost lineno

Ignore file generated by ctags