Factor out stereotypical ways of getting variable indices.
More informative comment describing INST_SYNTAX.
Working on a better compiler for [try]; found some bugs in previous compilation
code which aren't resolved yet.
Improving tests, fixed one case.
Fix the problems with code generation; behavior now appears correct.
[779d38b996]: Make the 'try' compiler handle -during right and compile some
more cases than it did before.
Improve compatibility detection for <time.h> and <sys/stat.h>: 
- Move <time.h> before other includes on Windows, so we are sure the time_t definition being checked doesn't come from <sys/types.h>. 
- Padding at the end of Tcl_StatBuf doesn't influcence binary compatibility, so relax panic check accordingly.
Improve compatibility detection for <time.h> and <sys/stat.h>: 
- Move <time.h> before other includes on Windows, so we are sure the time_t definition being checked doesn't come from <sys/types.h>. 
- Padding at the end of Tcl_StatBuf doesn't influcence binary compatibility, so relax panic check accordingly.