java: add push-parser support

java: add push-parser support

* data/lalr1.java: Capture the declarations as m4 macros to avoid
duplication.  When push parsing, the declarations occur at the class
instance level rather than within the parse() function.

Change the way that the parser state is initialized.  For
push-parsing, the parse state declarations are moved to
"push_parse_initialize()", which is called on the first invocation of
"push_parse()". The %initial-action code is also inserted after the
invocation of "push_parse_initialize()".

The body of the parse loop is modified to return values at appropriate
points when doing push parsing.  In order to make push parsing work,
it is necessary to divide YYNEWSTATE into two states: YYNEWSTATE and
YYGETTOKEN. On the first call to push_parse(), the state is
YYNEWSTATE. On all later entries, the state is set to YYGETTOKEN. The
YYNEWSTATE switch arm falls through into YYGETTOKEN. YYGETTOKEN
indicates that a new token is potentially needed.  Normally, with a
pull parser, this new token would be obtained by calling "yylex()". In
the push parser, the value YYMORE is returned to the caller. On the
next call to push_parse(), the parser will return to the YYGETTOKEN
state and continue operation.

* tests/javapush.at: New test file for java push parsing.
* tests/testsuite.at: Use it.
* tests/local.mk: Adjust.
* doc/bison.texi (Java Push Parser Interface): New.

Signed-off-by: Akim Demaille <akim@lrde.epita.fr>