…lly registered languages
First of all, this is done to support exceptions for the Mojo language,
but it's done in a way that will benefit any other plugin language.
1. I added a new lldb-dap CLI argument (not DAP field) called
`pre-init-commands`. These commands are executed before DAP
initialization. The other `init-commands` are executed after DAP
initialization. It's worth mentioning that the debug adapter returns to
VSCode the list of supported exception breakpoints during DAP
initialization, which means that I need to register the Mojo plugin
before that initialization step, hence the need for `pre-init-commands`.
In general, language plugins should be registered in that step, as they
affect the capabilities of the debugger.
2. I added a set of APIs for lldb-dap to query information of each
language related to exception breakpoints. E.g. whether a language
supports throw or catch breakpoints, how the throw keyword is called in
each particular language, etc.
3. I'm realizing that the Swift support for exception breakpoints in
lldb-dap should have been implemented in this way, instead of hardcoding
it.