yacc.c: support "%define api.pure full"

yacc.c: support "%define api.pure full"

This makes the interface for yyerror() pure without the need for a spurious
parse_param.

* data/yacc.c (b4_pure_if, b4_pure_flag): New definition, accept three states.
(b4_yacc_pure_if): Rename as...
(b4_yyerror_arg_loc_if): This, and use b4_pure_flag.
* tests/actions.at (%define api.pure): Modernize.
* test/calc.at (Simple LALR Calculator): Modernize.
* tests/local.at (AT_YYERROR_ARG_LOC_IF): Adjust.