Type annotations for instruction operands are omitted, e.g.
```
%3 = struct $S(%1, %2)
```
Operand types are redundant anyway and were only used for sanity checking in the SIL parser.
But: operand types _are_ printed if the definition of the operand value was not printed yet.
This happens:
* if the block with the definition appears after the block where the operand's instruction is located
* if a block or instruction is printed in isolation, e.g. in a debugger
The old behavior can be restored with `-Xllvm -sil-print-types`.
This option is added to many existing test files which check for operand types in their check-lines.
I suspect there are latent bugs here with generic-class-constrained existentials,
same-element requirements involving packs, etc. We can't assume that the
local archetypes don't have "hidden" dependencies on the outer parameters
that are not encoded in the thunk's interface type.
Invertible protocols are currently always mangled with `Ri`, followed by
a single letter for each invertible protocol (e.g., `c` and `e` for
`Copyable` and `Escapable`, respectively), followed by the generic
parameter index. However, this requires that we extend the mangling
for any future invertible protocols, which mean they won't be
backward compatible.
Replace this mangling with one that mangles the bit # for the
invertible protocol, e.g., `Ri_` (followed by the generic parameter
index) is bit 0, which is `Copyable`. `Ri0_` (then generic parameter
index) is bit 1, which is `Escapable`. This allows us to round-trip
through mangled names for any invertible protocol, without any
knowledge of what the invertible protocol is, providing forward
compatibility. The same forward compatibility is present in all
metadata and the runtime, allowing us to add more invertible
protocols in the future without updating any of them, and also
allowing backward compatibility.
Only the demangling to human-readable strings maps the bit numbers
back to their names, and there's a fallback printing with just the bit
number when appropriate.
Also generalize the mangling a bit to allow for mangling of invertible
requirements on associated types, e.g., `S.Sequence: ~Copyable`. This
is currently unsupported by the compiler or runtime, but that may
change, and it was easy enough to finish off the mangling work for it.
Reabstraction thunks mangle generic signatures and are now including
inverse requirements (i.e., suppressions). Since these symbols are
always `shared`, they're not ABI so it's OK that they're now different,
to distinguish them from thunks with signatures that lack the inverses.
The result-reabstraction code doesn't need to handle cleanups properly
during the planning phase because of course we don't have any values
yet. That is not true of argument reabstraction, so we need to make
sure that the recursive emitters can produce values with cleanups
so that we can collect and forward those cleanups correctly when
emitting the call.
As part of this, I've changed the code so that it should forward
outer addresses to inner address more consistently; it wouldn't
have done this before if we were breaking apart or assembling
a pack. I'm not sure I can directly test this without figuring
out a way to get SILGen to reabstract both sides of a function,
though.
I'm not sure this is really doing borrowed vs owned arguments
correctly, if e.g. we need to rebstract one component of a tuple
that's otherwise borrowed.
