* parse.c (parse_fprintf): New function used to avoid calls to
fprintf in bison parser generated debug code.
* parser-defs.h: Declaration of new parse_fprintf function.
* ada-exp.y, c-exp.y, f-exp.y, jv-exp.y, m2-exp.y, p-exp.y:
Set YYDEBUG to 1 by default.
Set YYFPRINTF as parse_fprintf.