Ruby

Add line_count field to rb_ast_body_t

This patch adds int line_count field to rb_ast_body_t structure.
Instead, we no longer cast script_lines to Fixnum.

Background¶

Ref https://github.com/ruby/ruby/pull/10618

In the PR above, we have decoupled IMEMO from rb_ast_t.
This means we could lift the five-words-restriction of the structure
that forced us to unionize rb_ast_t * and FIXNUM in one field.

Relating refactor¶

• Remove the second parameter of rb_ruby_ast_new() function

Attention¶

I will remove a code that assigns -1 to line_count, in rb_binding_add_dynavars()
of vm.c, because I don't think it is necessary.
But I will make another PR for this so that we can atomically revert
in case I was wrong (See the comment on the code)