swift234

Add an option for diagnostics -- PointsToFirstBadToken

Diagnostics that point to the first bad token are marked with this option in
Diagnostics.def.  Parser::diagnose treats the source location of such
diagnostics in a special way: if source location points to a token at the
beginning of the line, then it moves the diagnostic to the end of the previous
token.

This behaviour improves experience for "expected token X" diagnostics.


Swift SVN r7965