integration
Motivation: libIDE clients should be simple, and they should not have to
translate token-based SourceRanges to character locations.
This also allows us to remove the dependency of DiagnosticConsumer on the
Lexer. Now the DiagnosticEngine translates the diagnostics to CharSourceRanges
and passes character-based ranges to the DiagnosticConsumer.
Swift SVN r7173
If the completion prefix has a '.' behind it, guesstimate a context expression by lexing backward through an identifier(.identifier)* dotted path, then attempt to parse and typecheck that expression to decide on a base type in which to find completions.
Swift SVN r4063
actually render emitted diagnostics. This is both a useful
generalization (we expect to have a number of other
DiagnosticConsumers down the road, as Clang does) and is also
important now to avoid a layering violation when adjusting the source
location at the end of a SourceRange to the end of the token.
Swift SVN r850
