This introduces a new substitution for use in the CAS tests. The plain
variant of the target frontend invokes the tool with the variant target
triple and resource dir only. This allows us to properly invoke the
frontend for the CAS tests.
Add a script to build all dependencies for explicit module build in one
step. This reduces the boiling plate code needed to write a test for
explicit module build and allows the test to be more cross platform and
resilient to module dependencies changes.
These test commands were relying on an arcane Unix specific behaviour
that is non-portable to execute the commands. Python scripts cannot be
run and must be interpreted - they must specify the interpreter.
Explicitly invoke the tools with the configured python interpreter to
allow running the tool on other platforms.
Use IncludeTreeFileList instead of full feature CASFS for swift
dependency filesystem. This allows smaller CAS based VFS that is smaller
and faster. This is enabled by the CAS enabled compilation does not
need to iterate file system.
rdar://136787368
Preliminary caching support for macro:
* Inserting the plugin into the CASFS
* Lookup plugin via physical file system
For future better support, we should teach dependency scanner to resolve
macros and return the resolved plugins to swift-frontend.
rdar://121873571
