These are tests that fail in the next commit without this flag. This
does not add -verify-ignore-unrelated to all tests with -verify, only
the ones that would fail without it. This is NFC since this flag is
currently a no-op.
Import simple CPP macro aliases as aliases in Swift. Extend the macro
importer to import the following construct:
```
#define alias aliasee
```
as the following Swift construct:
```
@_transparent @inline(__always)
var alias: type(of: aliasee) {
aliasee
}
```
This improves the QoI for Windows where there is a universal define
(`UNICODE`) which normally is used for translating APIs between ANSI and
Unicode variants, e.g.:
```
#if defined(UNICODE)
#define MessageBox MessageBoxW
#else
#define MessageBox MessageBoxA
#endif
```
Global variables which are non-const also have a setter synthesized:
```
@_transparent @inline(__always)
var alias: type(of: aliasee) {
get { return aliasee }
set { aliasee = newValue }
}
```
