* NEWS: Document minor wording changes in diagnostics of

* NEWS: Document minor wording changes in diagnostics of
Bison-generated parsers.
* data/glr.c (yyMemoryExhausted): Renamed from yyStackOverflow.
Remove unused formals.  All uses changed.
(yyreportAmbiguity): "ambiguity detected" -> "syntax is ambiguous".
(yyparse): Rename yyoverflowlab to yyexhaustedlab.
* data/yacc.c (yyparse): "parser stack overflow" -> "memory exhausted".
Rename yyoverflowab to yyexhaustedlab.
When memory exhaustion occurs during syntax-error reporting,
report it separately rather than in a single diagnostic; this
eases translation.
* doc/bison.texinfo (Memory Management): Renamed from Stack Overflow.
(Memory Exhausted): Renamed from Parser Stack Overflow.
Revamp wording slightly to prefer "memory exhaustion".
* tests/actions.at: "parser stack overflow" -> "memory exhausted".