Instead of appending a character for each substitution, we now prefix the substitution with the repeat count, e.g.
AbbbbB -> A5B
The same is done for known-type substitutions, e.g.
SiSiSi -> S3i
This significantly shrinks mangled names which contain large lists of the same type, like
func foo(_ x: (Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int, Int))
rdar://problem/30707433
In 74d979f0ac, the policy was changed
so that only value type accessors are ever marked transparent, and
not class accessors.
This was intended to fix a bug where inlining an accessor of an
Objective-C-derived class across module boundaries caused a linker
failure because the accessor referenced a field offset variable,
which has hidden visibility.
However, this also caused a performance regression for Swift native
classes. Bring back the old behavior for Swift native classes in
non-resilient modules.
Fixes <rdar://problem/29884727>.
(and any other member with higher access control than its enclosing type)
There's no effect, but it is now considered legal and the compiler will
no longer warn about it. This allows an API author to prototype their
API with proper access levels and still limit the top-level type.
If the new getEffectiveAccess computation turns out to be expensive, we
can cache the result.
Note that the compiler will still warn when putting a public member
inside an extension explicitly marked internal, because the extended
type could be public and then including a public member would be valid.
It is also still an error to put a public member inside a constrained
extension of an internal type, though I think this one is safe to
relax later.
Progress on SE-0025 ('private' and 'fileprivate')
