This allows us to more easily test behavior for build servers that have different behavior than SwiftPM and compile commands without having to implement the build server in Python.
There were a few places that options only took place *after* determining
a build system, even though we have multiple that impact the search (eg.
`defaultBuildSystem` and `searchPaths`).
Additionally track project root and configuration paths separately, so
that when searching for implicit workspaces we can make sure to skip
creating duplicates.
We made quite a few fixes recently to make sure that path handling works correctly using `URL` on Windows. Use `URL` in most places to have a single type that represents file paths instead of sometimes using `AbsolutePath`.
While doing so, also remove usages of `TSCBasic.FileSystem` an `InMemoryFileSystem`. The pattern of using `InMemoryFileSystem` for tests was never consistently used and it was a little confusing that some types took a `FileSystem` parameter while other always assumed to work on the local file system.
If a BSP server crashes, we should try to relaunch it. Use a similar relaunch logic as the one we use for `clangd`: Try restarting immediately unless the BSP server has crashed within the last 30 seconds, in which case we delay the restart by 10s.
rdar://136311009
Fixes#1686
The interaction to an out-of-process BSP server still went through the `BuildServerBuildSystem`, which doesn’t forward all messages to the build system and uses the old push-based model for build settings.
If we discover that the BSP server supports the new pull-based build settings model, we now forward all methods to it directly, without going through `BuiltInBuildSystemAdapter`, which has been renamed to `LegacyBuildServerBuildSystem`.
rdar://136106323
rdar://127606323
rdar://126493405
Fixes#1226Fixes#1173
