cobol: Variety of small changes in answer to cppcheck diagnostics.

cobol: Variety of small changes in answer to cppcheck diagnostics.

Remove non-ASCII input and blank lines from gcobol.1. Restrict
cobol.clean target to compiler object files.

gcc/cobol/ChangeLog:

	* Make-lang.in: cobol.clean does not remove libgcobol files.
	* cdf.y: Suppress 1 cppcheck false positive.
	* cdfval.h (scanner_parsing):  Partial via cppcheck for PR119324.
	* gcobol.1: Fix groff errors.
	* gcobolspec.cc (append_arg): Const parameter.
	* parse_ante.h (intrinsic_call_2): Avoid NULL dereference.

(cherry picked from commit 70c3dd9a81cdefcaf24a66ec0c1ceddf5d3984dd)