PR 1304
* parse.cxx (lexer): Take systemtap_session argument.
(lexer::scan): Support $1..$NNNN and @1...@NNNN expansion.
* stap.1.in: Document this.
* testsuite/semok/args.stp: New test.
* translate.cxx (var::init, emit_global): Emit code to allow
named module parameters to initialize global string/number scalars.
* stap.1.in: Don't document this yet.