Add support to Swift Concurrency backport using swift-stdlib-tool (#69)

* Add swift config  swift_stdlib_tool_run_on_subfolders to prevent to import libraries needed for 3rd party libs that supports iOS below 12
Add swift config swift_stdlib_tool_import_only_concurrency_lib to import only libswift_concurrency* libraries

* change from boolean type to Optional<Boolean> to match initializers

Co-authored-by: Lucas Marcal <[email protected]>

Add support to Swift Concurrency backport using swift-stdlib-tool (#69)

* Add swift config  swift_stdlib_tool_run_on_subfolders to prevent to import libraries needed for 3rd party libs that supports iOS below 12
Add swift config swift_stdlib_tool_import_only_concurrency_lib to import only libswift_concurrency* libraries

* change from boolean type to Optional<Boolean> to match initializers

Co-authored-by: Lucas Marcal <[email protected]>

On 3.10 some `collections` classes have been moved to (#68)

`collections.abc` and it causes Buck 1 to crash. This diff fixes those
instances.

Really pex should be upgraded, but I made an attempt and it was very difficult
due to our custom changes to pex.

Co-authored-by: Lucas Marcal <[email protected]>

fix lldb AST serialization while erroneously trying to load .swiftint…

…erface files.

Revert "use -Wl instead of -Xlinker for oso prefix"

This reverts commit 4e44f22.

cleanup unused variables

Fix incremental build

Fix VFSOverlay generation

separate index while building from incremental compilation

Support VFSOverlay

Upgrade JUnixSocket to 2.4.0 for Apple Silicon support (drop this com…

…mit before rebasing) (#67)