* data/Makefile.am (dist_pkgdata_DATA): Add push.c.

* data/Makefile.am (dist_pkgdata_DATA): Add push.c.
* data/c.m4 (YYPUSH): New.
(b4_push_if): New macro.  Use it instead of #ifdef YYPUSH.
* src/getargs.c (push_parser): New var.
* src/getargs.h (push_parser): New declaration.
* src/output.c (prepare): Add macro insertion of `push_flag'.
* src/parse-gram.y (PERCENT_PUSH_PARSER): New token.
(prologue_declaration): Parse %push-parser.
* src/scan-gram.l: Scan new PERCENT_PUSH_PARSER token.
* tests/calc.at (_AT_CHECK_CALC_ERROR): Add "Return" and "Now" to
list of removed lines from the traces observed.
(AT_CHECK_CALC_LALR): Added push parser tests.