From my point of view, a type that contains a code completion token can still be parsed as a type and as such, `canParseType` should return `true` for e.g. `#^COMPLETE^#` or `SomeType.#^COMPLETE^#`.
Changing this fixes an issue that caused no type completions to be shown inside a enum case decl.
Fixes rdar://71984715
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
