Also, make it more tolerant to instructions and builtins, which are not explicitly handled.
This avoids crashes when new instructions are added. We got lucky that this didn't happen so far.
Add a boolean parameter `salvageDebugInfo` to `Context.erase(instruction:)`.
Sometimes it needs to be turned off because the caller might require that after erasing the original instruction the operands no users anymore.
It derives the address of the first element of a vector, i.e. a `Builtin.FixedArray`, from the address of the vector itself.
Addresses of other vector elements can then be derived with `index_addr`.
Instead of passing in the substituted type, we pass in the
InFlightSubstitution. This allows the substituted type to be
recovered if needed, but we can now skip computing it for
the common case of LookUpConformanceInSubstitutionMap.
Add a note explaining that dependence on closure captures is not
supported. Otherwise, the diagnostics are very confusing:
"it depends on a closure capture; this is not yet supported"
This replaces the oddly-named mapIntoTypeExpansionContext() method
on SubstitutionMap itself in favor of a global function, just like
the ones that take Type and ProtocolConformanceRef.
If the method is a default witness methods (`selfType` != nil) it has generic self type.
In this case the generic self parameter is at depth 0 and the actual generic parameters of the substitution map are at depth + 1, e.g:
```
@convention(witness_method: P) <τ_0_0><τ_1_0 where τ_0_0 : GenClass<τ_1_0>.T>
^ ^
self params of substitution map at depth + 1
```
* move it from the SIL to the AST module (where it belongs)
* change the signature of `diagnose` from `diagnose(location, .some_error)` to `diagnose(.some_error, at: location)`
* add an overload to allow passing a `SIL.Location` directly to `diagnose`
* add a `Diagnostic : Error` utility struct which allows throwing a `Diagnostic`
Store specialize witness tables in a separate lookup table in the module. This allows that for a normal conformance there can exist the original _and_ a specialized witness table.
Also, add a boolean property `isSpecialized` to `WitnessTable` which indicates whether the witness table is specialized or not.
When a generic function has potentially Escapable outputs, those outputs
declare lifetime dependencies, which have no effect when substitution
leads to those types becoming `Escapable` in a concrete context.
This means that type substitution should canonically eliminate lifetime
dependencies targeting Escapable parameters or returns, and that
type checking should allow a function value with potentially-Escapable
lifetime dependencies to bind to a function type without those dependencies
when the target of the dependencies is Escapable.
Fixes rdar://147533059.
Specifically:
1. I made it so that thunks from caller -> concurrent properly ignore the
isolated parameter of the thunk when calling the concurrent function.
rdar://148112362
2. I made it so that thunks from concurrent -> caller properly create a
Optional<any Actor>.none and pass that into the caller function.
rdar://148112384
3. I made it so that in cases where we are assigning an @Sendable caller to a
non-sendable caller variable, we allow for the conversion as long as the
parameters/results are sendable as well.
rdar://148112532
4. I made it so that when we generate a thunk from @execution(caller) ->
@GlobalActor, we mangle in @GlobalActor into the thunk.
rdar://148112569
5. I discovered that due to the way we handle function conversion expr/decl ref
expr, we were emitted two thunks when we assigned a global @caller function to a
local @caller variable. The result is that we would first cast from @caller ->
@concurrent and then back to @caller. The result of this would be that the
@caller function would always be called on the global queue.
rdar://148112646
I also added a bunch of basic tests as well that showed that this behavior was
broken.
