Change to automatically insert #include of header files when they are specified

[ydah]

Resolve: #14 (comment)

This PR change to automatically insert #include of header files when they are specified.
Bison will automatically embed #include header files when run with the -H, --header=[FILE] or -d options.
So, we make header file is include automatically when -h, --header or -d option is passed.

We found that if Lrama was made to behave the same as Bison as is, it would fail to build ruby.
The use of the -H, --header=[FILE] or -d options to include header files seemed to cause problems in cases like ripper.y, where ripper.h was not included from ripper.c.
So we added the --auto-include option to automatically add an include statement to the header file when this option is specified. How about it?

[yui-knk]

Thanks for the PR. My expectation is that a header file is included automatically when -h, --header or -d option is passed.
I suspect the cause of ripper build failure is that #include is placed on very beginning of output file so that a lot of declarations, e.g. VALUE, NODE and so on, are not defined when the header file is included.
Could you try the below?

1. Rebase or merge current master to reflect Sync yacc.c to yacc.h #133
2. Update

   lrama/template/bison/yacc.c

   Line 104 in 21e405a

   /* Use api.header.include to #include this header

   like below?

<%# b4_header_include_if -%>
<%- if output.header_file_path -%>
#include <%= option.include_header %>
<%- else -%>
/* Use api.header.include to #include this header
   instead of duplicating it here.  */
...
  <%-# b4_percent_code_get([[provides]]). %code is not supported -%>
  <%-# b4_cpp_guard_close([b4_spec_mapped_header_file]) -%>
    <%- if output.spec_mapped_header_file -%>
#endif /* !<%= output.b4_cpp_guard__b4_spec_mapped_header_file %>  */
    <%- end -%>
<%- end -%>
<%# b4_declare_symbol_enum -%>

[ydah]

Thank you so much! I updated this PR.

[yui-knk]