Disable periadic diagnostic update on language-server on CI (#7445)

The "textDocument/publishDiagnostics" Notification in the official
Language Server Protocol, or LSP for short, is a notification that
the server sends to the client such as VSCode or Visual Studio
without the client having to ask for it. Its purpose is to provide
a list of errors, warnings, or other informational "squiggles" for
a specific file.

Because the notification is an asynchronous push notification, it
is receieved as an unexpected RPC message during the slang-test CI
tests. When a notificatoin is unexpectedly sent to slang-test, the
communication goes out-of-sync and the rest of language-server
based tests intermittently fails.

In order to address the problem, this PR adds a new command-line
argument to change the behavior of the notification and it will
be sent in a more deterministic manner where the notification can
be sent only in one of three cases: didOpen, didChange, and
didClose. Because these evets are only ways to cause a new
notification, we can still expect to get the same diagnostic
messages without missing any of them. For slang-test CI test,
this new option will be used to make the notification more
deterministic.

0 files changed, 0 insertions, 0 deletions