It is no longer necessary to produce `.swiftinterface` files the support older
compilers that lack support for the NoncopyableGenerics feature. Cleaning this
up makes the stdlib `.swiftinterface` far more readable.
While the new parameter is added in a compatible way where code which
does not refer to it will get a defaulted nil value; since we refer to a
new parameter name in source, we need to guard it with a language
feature -- as old compilers will not have this new name available.
This should prevent a potential condfail issue.
Out of an abundance of caution, we:
1. Left in parsing support for transferring but internally made it rely on the
internals of sending.
2. Added a warning to tell people that transferring was going to
be removed very soon.
Now that we have given people some time, remove support for parsing
transferring.
rdar://130253724
The handling of multi-basic-block control flow in `defer` blocks looks like it
was left incomplete and completely untested; I fixed a few obvious problems but
it still completely lacks any analysis of conditional reinitializations. For now,
change it to treat attempted reinitializations as uses-after-consumes so we raise
reliable errors now instead of emitting code that causes memory corruption at
runtime. Fixes rdar://129303198.
TLDR: This makes it so that we always can parse sending/transferring but changes
the semantic language effects to be keyed on RegionBasedIsolation instead.
----
The key thing that makes this all work is that I changed all of the "special"
semantic changes originally triggered on *ArgsAndResults to now be triggered
based on RegionBasedIsolation being enabled. This makes a lot of sense since we
want these semantic changes specifically to be combined with the checkers that
RegionBasedIsolation turns on. As a result, even though this causes these two
features to always be enabled, we just parse it but we do not use it for
anything semantically.
rdar://128961672
Some compilers have the NoncopyableGenerics feature enabled via
interesting mechanisms but do not have ConformanceSuppression. To
support such compilers, the NoncopyableGenerics feature must appear
before ConformanceSuppression in the list of features. Otherwise, when
parsing the portion of the swiftinterface corresponding to an entity
which involves both features, the first check will be for
NoncopyableGenerics (which that old compiler has) and the code inside
will involve ConformanceSuppression (which that old compiler does not
have).
rdar://128611158
