eliminate use of Bison yytname

gcc/cobol/cdf.y

gcc/cobol/cdftok.awk

gcc/cobol/parse.y

gcc/cobol/parse_ante.h

gcc/cobol/scan.l

gcc/cobol/scan_ante.h

gcc/cobol/token_names.h

gcc/cobol/token_names.h.gen

gcc/cobol/util.cc