* data/c.m4 (b4_c_ansi_args): Recognize functions with no

* data/c.m4 (b4_c_ansi_args): Recognize functions with no
arguments and output `void'.
(b4_c_function): Rename as...
(b4_c_function_def): this.
(b4_c_function_decl, b4_c_ansi_function_def)
(b4_c_ansi_function_decl): New.
Change the interpretation of the arguments: before `int, foo', now
`int foo, foo'.
* data/yacc.c (yyparse): Prototype and define thanks to these.
Adjust b4_c_function_def uses.
* data/glr.c (yyparse): Likewise, but ANSI only.