Fix no available capacity error and other minor fixes.

[ssttuu]

Changes

• This PR increases the debug event channel size to avoid dropping events in large code bases.
• Fixes the extension.js exit handler when the process segfaults.
• Removes unsafe impl Send from all SB* cpp structs.
• Fixes the drop_pyobject function signature to return void since that's what the rust signature expects when calling std::mem::transmute.
• Adds null pointer checks to the python interface.

This should resolve #1273, #1140, and #1010.

Fixes #1273.

Verification Evidence

I made my changes, then ran the following:

$ mkdir build
$ cd build
$ cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/toolchain-aarch64-apple-darwin.cmake -DLLDB_PACKAGE=/Users/stu/Downloads/lldb--aarch64-apple-darwin.zip

$ make vsix_full
Archive:  /Users/stu/Downloads/lldb--aarch64-apple-darwin.zip
[  0%] Built target lldb
[  3%] Built target extension
[ 11%] Built target lang_support
[ 15%] Performing build step for 'cargo_build'
   Compiling codelldb v1.0.0 (/Users/stu/dev/vadimcn/codelldb/adapter/codelldb)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.02s
[ 19%] No install step for 'cargo_build'
[ 23%] Completed 'cargo_build'
[ 42%] Built target cargo_build
[ 42%] Built target codelldb_exe
[ 76%] Built target codelldb_scripts
[ 76%] Built target adapter

> [email protected] vsce
> vsce package --baseContentUrl https://github.com/vadimcn/codelldb/blob/v1.11.4-dev.2505021902 --baseImagesUrl https://github.com/vadimcn/codelldb/raw/v1.11.4-dev.2505021902 --target darwin-x64 -o /Users/stu/dev/vadimcn/codelldb/build/codelldb-full.vsix

 WARNING  LICENSE.md, LICENSE.txt or LICENSE not found
Do you want to continue? [y/N] Y
 DONE  Packaged: /Users/stu/dev/vadimcn/codelldb/build/codelldb-full.vsix (992 files, 43.46MB)
[100%] Built target vsix_full

I opened vscode and loaded the extension directly from the .vsix file.

Running the debugger now works as expected!

[ssttuu]

I copied the latest version from here:
https://microsoft.github.io/debug-adapter-protocol/debugAdapterProtocol.json

It's just slight documentation changes.

[ssttuu]

Add null pointer checks to ensure there are no issues here during evaluation.

[ssttuu]

AFAICT, none of the SB* structs should be Send. Everything continues working with these removed. Let me know what you think @vadimcn.

[ssttuu]

I made this change because the type signature for drop_pyobject returns void.

drop_pyobject: unsafe extern "C" fn(obj: *mut c_void)

[vadimcn]

Thanks!

However, this PR contains a lot of unrelated changes. Based on the error message, the only channel that needs its capacity increased is the DAP output queue here (which I’ve already updated in my dev branch).

You make a valid point about drop_pyobject and adapterProcess.on('exit', ...), so I’ll fix those.