* move the apply of partial_apply transformation from simplify-apply to simplify-partial_apply
* delete dead partial_apply instructions
* devirtualize apply, try_apply and begin_apply
This allows to run the NamedReturnValueOptimization only late in the pipeline.
The optimization shouldn't be done before serialization, because it might prevent predictable memory optimizations in the caller after inlining.
It converts a lazily initialized global to a statically initialized global variable.
When this pass runs on a global initializer `[global_init_once_fn]` it tries to create a static initializer for the initialized global.
```
sil [global_init_once_fn] @globalinit {
alloc_global @the_global
%a = global_addr @the_global
%i = some_const_initializer_insts
store %i to %a
}
```
The pass creates a static initializer for the global:
```
sil_global @the_global = {
%initval = some_const_initializer_insts
}
```
and removes the allocation and store instructions from the initializer function:
```
sil [global_init_once_fn] @globalinit {
%a = global_addr @the_global
%i = some_const_initializer_insts
}
```
The initializer then becomes a side-effect free function which let's the builtin-simplification remove the `builtin "once"` which calls the initializer.
Eliminate the redundant instruction pair
```
%t = tuple (%0, %1, %2)
(%3, %4, %5) = destructure_tuple %t
```
and replace the results %3, %4, %5 with %0, %1, %2, respectively.
The same for structs.
* Check if the address in question is even visible from outside the function
* Return the memory effects of the called function
Also, add a new API `Instruction.memoryEffects`, which is internally used by `mayReadFromMemory` et al.
This reverts commit e9dedf3c27.
The revert is required as foreign reference types are available for SwiftStdlib 5.8 and above, but the Swift compiler
sources back deploy to older stdlibs as well.
This is in preparation for wiring up debug info support for noncopyable
values. Originally this flag name made sense since it was set when we performed
consume operator checking. Now I am going to use it for noncopyable types as
well. I think the new name uses_moveable_value_debuginfo actually describes what
the flag is supposed to do, tell IRGen that the value may be moved since it
needs to use moveable value debug info emission.
A type (mostly classes) can be attributed with `@_semantics("arc.immortal")`.
ARC operations on values of such types are eliminated.
This is useful for the bridged SIL objects in the swift compiler sources.
