completion token
This is required to handle cases like fooObject.#^A^#.bar where code completion
is invoked inside the ".." token. Previously, the token would not be split and
the lexer would produce an incorrect tokenization for this case. Now we
produce ".", tok::code_complete, ".".
Swift SVN r6635
Documentation comment says that it should return a 0-based offset, but it
actually returns a 1-based offest.
Code completion tests did not catch this bug because the only consequence is
that the code completion token is shifted one character to the right, and in
all code completion tests we had a space after the code completion token.
Swift SVN r6566
* Added a mode in swift-ide-test to test code completion. Unlike c-index-test,
the code completion token in tests is a real token -- we don't need to
count lines and columns anymore.
* Added support in lexer to produce a code completion token.
* Added a parser interface to code completion. It is passed down from the
libFrontend to the parser, but its functions are not called yet.
* Added a sketch of the interface of code completion consumer and code
completion results.
Note: all this is not doing anything useful yet.
Swift SVN r6128
