Bison 3.0 was released in 2013, and the current Debian stable (buster)
has version 3.3.2.
* m4/bison.m4: Remove -Wno-precedence and -Wno-empty-rule, keep
-Wno-deprecated just to protect from future deprecation warnings that
would be interpreted as errors.
* spot/parseaut/parseaut.yy, spot/parsetl/parsetl.yy: Use %empty
rules, prefer %precedence over %nonassoc, update %error-versbose and
%name-prefix to their more modern equivalent.
* spot/misc/trival.hh (maybe): Mark this function as noexcept to
please the compiler while compiling the parsers.
We still want to remain compatible with Bison 2.7 so instead of fixing
all the new errors reported by 3.0 we silence some warning. We should
fix these for good once Bison 3.0 is more widespread.
* m4/bison.m4: New file. Test if bison support -Wno-empty-rule and
-Wno-deprecated. Define BISON and BISON_EXTRA_FLAGS.
* configure.ac: Do not test for yacc, use the above test instead.
* src/dstarparse/Makefile.am, src/eltlparse/Makefile.am,
src/kripkeparse/Makefile.am, src/ltlparse/Makefile.am,
src/neverparse/Makefile.am, src/tgbaparse/Makefile.am: Use BISON
and BISON_EXTRA_FLAGS.
* src/ltlparse/ltlparse.yy: Fix or and remove useless %right/%nonassoc
settings.
* src/eltlparse/eltlparse.yy: Likewise, and remove "%pure-parser".
