Replace deprecated bison commands

[JCGoran]

TODO:

• [ ] according to the docs, updating name-prefix to api.prefix is a bit non-trivial, and a naive fix results in compilation errors. For reference, here's the relevant section:

  The '%name-prefix "xx"' directive is deprecated in favor of '%define
  api.prefix {xx}' since Bison 3.0, but no warning was issued.  These
  directives are slightly different, you might need to adjust your code.
  %name-prefix renames only symbols with external linkage, while api.prefix
  also renames types and macros, including YYDEBUG, YYTOKENTYPE,
  yytokentype, YYSTYPE, YYLTYPE, etc.
  
  Users of Flex that move from '%name-prefix "xx"' to '%define api.prefix
  {xx}' will typically have to update YY_DECL from
  
  #define YY_DECL int xxlex (YYSTYPE *yylval, YYLTYPE *yylloc)
  
  to
  
  #define YY_DECL int xxlex (XXSTYPE *yylval, XXLTYPE *yylloc)