This was never used to generate a .swiftinterface, so can be safely removed. It
was used to guard compiler fixes that might break older .swiftinterface
files. Now, we guard the same fixes by checking the source file type.
Find all the usages of `--enable-experimental-feature` or
`--enable-upcoming-feature` in the tests and replace some of the
`REQUIRES: asserts` to use `REQUIRES: swift-feature-Foo` instead, which
should correctly apply to depending on the asserts/noasserts mode of the
toolchain for each feature.
Remove some comments that talked about enabling asserts since they don't
apply anymore (but I might had miss some).
All this was done with an automated script, so some formatting weirdness
might happen, but I hope I fixed most of those.
There might be some tests that were `REQUIRES: asserts` that might run
in `noasserts` toolchains now. This will normally be because their
feature went from experimental to upcoming/base and the tests were not
updated.
Both of these can cause us to insert destroy_addr in the wrong locations.
1. The first causes us to insert destroys for parts of values that are not
actually on the boundary since we didn't use our mask and instead used all of
the liveness information.
2. We were merging successor information using '&=' instead of '|=. This caused
a problem if we had multiple regions for the same successor. In such a case, we
would not have anything in common for the regions causing us to not have any
bits in common, resulting in us inserting too many destroy_addr instead of
skipping as we were supposed to.
rdar://112434492
The reason why we want to do this is that if we treat it as a true forwarding
use, we will visit the uses of the trivial value and treat those as liveness
uses. Since the trivial value is not tied to the lifetime of the underlying
noncopyable value, this can be outside of the lifetime of said value causing a
memory lifetime error. By just treating the guaranteed forwarding instruction
with all trivial values as a liveness use, we avoid this problem.
I added a SIL test, a Swift test, and an Interpreter test that validates this
behavior.
rdar://111497657
