swift234

Dependency analysis: treat member operators as top-level "provides". (#3986)

We still do a global lookup for operators even though they are
syntactically declared within types now, so for dependency-tracking
purposes continue to treat that as declared at the top level.

This isn't where we actually want to be---ideally we can use the types
of the arguments to limit the dependencies to a member lookup (or pair
of member lookups)---but since the operator overloads /themselves/
participate in type-checking an expression, I'm not sure that's 100%
correct. For now, it's better to be conservative. (This means
dependency analysis for operators remains as lousy as it was in Swift
2, but it's not a regression.)

rdar://problem/27659972