Fix innumerable latent bugs with iterator invalidation and callback invocation.
Removes dead code earlier and chips away at all the redundant copies the compiler generates.
LinkNormal mode is used by the mandatory pipeline. It only needs
to deserialize what is necessary for code generation, that is
functions with shared linkage that must be emitted into the client.
This is technically a source break, but the @_fixed_layout attribute
is not official yet. If anyone really cares, we can make this
conditional on -swift-version 5 later, but I'd rather not.
This change is necessary so that we can give property initializers
non-public linkage. Currently they are public, because they can be
referenced from inlinable initializers.
Now that property initializers inside a @_fixed_layout type can
only reference public symbols, they no longer have to be public,
but making that change requires a bit more work.
Quiz: What does @_transparent on an extension actually *do*?
1) Make all members @_transparent?
2) Allow your members to be @_transparent?
3) Some other magical effect that has nothing to do with members?
The correct answer is 1), however a few places in the stdlib defined
a @_transparent extension and then proceeded to make some or all members
also @_transparent, and in a couple of places we defined a @_transparent
extension with no members at all.
To avoid cargo culting and confusion, remove the ability to make
@_transparent extensions altogether, and force usages to be explicit.
implemented with Builtin.Word
The definition Swift.Int is becoming heavily platform-dependent, please
avoid using it in SIL and IR tests unless Swift.Int is being tested and
can't be replaced with a fixed-width type (e.g., Int32).
Swift SVN r24720
This only tackles the protocol case (<rdar://problem/17510790>); it
does not yet generalize to an arbitrary "class" requirement on either
existentials or generics.
Swift SVN r19896
In most cases this means adding @public to things that get serialized;
in a few cases it means using a modern public stdlib API instead of
a legacy thing I was trying to keep @internal.
Swift SVN r19350
