This commit changes `struct parser_params` lastline and nextline
from `VALUE` (String object) to `rb_parser_string_t *` so that
dependency on Ruby Object is reduced.
`parser_string_buffer_t string_buffer` is added to `struct parser_params`
to manage `rb_parser_string_t` pointers of each line. All allocated line
strings are freed in `rb_ruby_parser_free`.
`:sym` was managed by `NODE_LIT` with `Symbol` object.
This commit introduces `NODE_SYM` so that
1. Symbol literal is detectable from AST Node
2. Reduce dependency on ruby object
`__FILE__` was managed by `NODE_STR` with `String` object.
This commit introduces `NODE_FILE` and `struct rb_parser_string` so that
1. `__FILE__` is detectable from AST Node
2. Reduce dependency ruby object
`__LINE__` was managed by `NODE_LIT` with `Integer` object.
This commit introduces `NODE_LINE` so that
1. `__LINE__` is detectable from AST Node
2. Reduce dependency ruby object
Introduce Universal Parser mode for the parser.
This commit includes these changes:
* Introduce `UNIVERSAL_PARSER` macro. All of CRuby related functions
are passed via `struct rb_parser_config_struct` when this macro is enabled.
* Add CI task with 'cppflags=-DUNIVERSAL_PARSER' for ubuntu.
