* data/lalr1.cc (b4_parse_param_decl, b4_parse_param_cons,
b4_cc_constructor_calls, b4_cc_constructor_call,
b4_parse_param_vars, b4_cc_var_decls, b4_cc_var_decl): New m4
definitions.
(yy::b4_parser_class_name::b4_parser_class_name): Take extra
parse-param arguments.
(yy::b4_parser_class_name): Declare instance variables to
hold parse-param arguments.
* tests/calc.at: s/value/semantic_value/ because value clashes
with a member of yy::b4_parser_class_name. Adjust C++ code
to handle %parse-param. Enable %parse-param test in C++.