Upgrade parsers to Bison >= 3.0

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.

m4/bison.m4

@@ -2,12 +2,7 @@ AC_DEFUN([adl_CHECK_BISON],
 [AC_ARG_VAR([BISON], [Bison parser generator])
 AC_CHECK_PROGS([BISON], [bison])
 if test -n "$BISON"; then
-   # Bison 3.0 has warning about issues that cannot be fixed in a
-   # compatible way with Bison 2.7.  Since we want to be compatible
-   # with both version AND use -Werror, disable those warnings.
-   # (Unfortunately -Wno-error=empty-rule,no-error=deprecated does not
-   # work: https://lists.gnu.org/archive/html/bug-bison/2013-09/index.html)
-   opt='-Wno-empty-rule -Wno-deprecated -Wno-precedence'
+   opt='-Wno-deprecated'
    if AM_RUN_LOG([$BISON $opt --version]); then
       BISON_EXTRA_FLAGS=$opt
    fi