Maintain the ability for older Swift compilers to read .swiftinterfaces
that make use of result builders by always emitting @_functionBuilder
rather than the newer @resultBuilder.
Make `make-unreadable` python 3 compatible. `POINTER` is now in
`ctypes` rather than in `ctypes.wintypes`. Use the new location which
is compatible across python 2 and python 3.
For cases like this:
```swift
struct X {}
struct Y {}
func overloaded<T>(_ value: T) -> T { value }
func overloaded<T>(_ value: T) -> Int { 0 }
func test(x: inout X, y: Y) {
x = overloaded(y)
}
```
Solver would record a `IgnoreAssignmentDestinationType` fix per overload,
`diagnoseForAmbiguity` could be used to properly diagnose ambiguity cases
like that.
Introduce a fix/diagnostic when there is a contextual mismatch
between source and destination types of the assignment e.g.:
```swift
var x: Int = 0
x = 4.0 // destination expects an `Int`, but source is a `Double`
```
We already have something called "module interfaces" -- it's the
generated interface view that you can see in Xcode, the interface
that's meant for developers using a library. Of course, that's also a
textual format. To reduce confusion, rename the new module stability
feature to "parseable [module] interfaces".
Fixes a longstanding issue where submodules with the same name in
different top-level modules weren't being sorted deterministically.
This doesn't come up very much in practice, and it would have been
hard to notice anything wrong, but it's good to be right.
It's not clear whether we'll actually need this feature in the long
run, but we certainly need it now because non-@usableFromInline
members can (currently) satisfy public requirements when a
@usableFromInline internal type conforms to a public protocol. In
these cases, we'll treat the witnesses as present but opaque, and
clients will perform dynamic dispatch when using them even when
a generic function gets specialized.
With this, we're able to generate a textual interface for the standard
library, compile it back to a swiftmodule, and use it to build a Hello
World program!
