to make prototypes for all functions declared here.
* cplus-dem.c: Avoid declaring xmalloc and xrealloc.
* c-exp.y: Rename SIGNED, OR, and AND to avoid conflict.
* environ.c: Include <stdio.h> before defs.h. Minor cleanup.
* ieee-float.h: Use PARAMS for prototypes; make some params const.
* ieee-float.c, valarith.c: Include <stdio.h>. Lint. b*=>mem*.
* m2-exp.y: Remove unused CONST; Rename OR and AND.
* utils.c: Avoid declaring malloc and realloc. Lint.
(request_quit): Accept signal-number parameter.
