This simplifies the handling of the subdirectories in the SIL and
SILOptimizer paths. Create individual libraries as object libraries
which allows the analysis of the source changes to be limited in scope.
Because these are object libraries, this has 0 overhead compared to the
previous implementation. However, string operations over the filenames
are avoided. The cost for this is that any new sub-library needs to be
added into the list rather than added with the special local function.
* a new [immutable] attribute on ref_element_addr and ref_tail_addr
* new instructions: begin_cow_mutation and end_cow_mutation
These new instructions are intended to be used for the stdlib's COW containers, e.g. Array.
They allow more aggressive optimizations, especially for Array.
Adjust `SILModule::createEmptyModule` to accept a
FileUnit or ModuleDecl, and pass the corresponding
context for SIL generation and parsing. This
change means that SIL parsing will now correctly
use a SourceFile associated context when in
single-file mode.
Because we were previously performing SIL parsing
during `performSema`, we were relying on the
pipeline being stopped before reaching the SIL
pipeline passes.
However under a lazy evaluation model, we can't
rely on that. Instead, just return an empty
SILModule if we encounter a parsing error.
This became necessary after recent function type changes that keep
substituted generic function types abstract even after substitution to
correctly handle automatic opaque result type substitution.
Instead of performing the opaque result type substitution as part of
substituting the generic args the underlying type will now be reified as
part of looking at the parameter/return types which happens as part of
the function convention apis.
rdar://62560867
Move the source files from ParserSIL into the SIL library and remove the
ParserSIL library. ParsersSIL doesn't need to be its own library and this change will
simplify our builds.