[lldb-vscode] Prior to running the launchCommands during a launch request set the launch info so the configured launch information is accessible by the launch commands.

[ashgti]

A small improvement to allow launchCommands to access the configured launch info.

[wallace]

THANKS

lldb/tools/lldb-vscode/README.md

 |**program**        |string|Y| Path to the executable to launch.
 |**args**           |[string]|| An array of command line argument strings to be passed to the program being launched.
 |**cwd**            |string| | The program working directory.
 |**env**            |dictionary| | Environment variables to set when launching the program. The format of each environment variable string is "VAR=VALUE" for environment variables with values or just "VAR" for environment variables with no values.
 |**stopOnEntry**    |boolean| | Whether to stop program immediately after launching.
 |**initCommands**   |[string]| | LLDB commands executed upon debugger startup prior to creating the LLDB target. Commands and command output will be sent to the debugger console when they are executed.
 |**preRunCommands** |[string]| | LLDB commands executed just before launching after the LLDB target has been created. Commands and command output will be sent to the debugger console when they are executed.
 |**stopCommands**   |[string]| | LLDB commands executed just after each stop. Commands and command output will be sent to the debugger console when they are executed.
+|**launchCommands** |[string]| | LLDB commands executed to launch the program. Commands and command output will be sent to the debugger console when they are executed.
 |**exitCommands**   |[string]| | LLDB commands executed when the program exits. Commands and command output will be sent to the debugger console when they are executed.
 |**terminateCommands** |[string]| | LLDB commands executed when the debugging session ends. Commands and command output will be sent to the debugger console when they are executed.
 |**sourceMap**      |[string[2]]| | Specify an array of path re-mappings. Each element in the array must be a two element array containing a source and destination pathname.
 |**debuggerRoot**   | string| |Specify a working directory to use when launching lldb-vscode. If the debug information in your executable contains relative paths, this option can be used so that `lldb-vscode` can find source files and object files that have relative paths.
 
 ## Attaching Settings
 
 When attaching to a process using LLDB you can attach in a few ways

lldb/tools/lldb-vscode/lldb-vscode.cpp

if (llvm::Error err = request_runInTerminal(request, timeout_seconds))
       error.SetErrorString(llvm::toString(std::move(err)).c_str());
   } else if (launchCommands.empty()) {
     // Disable async events so the launch will be successful when we return from
     // the launch call and the launch will happen synchronously
     g_vsc.debugger.SetAsync(false);
     g_vsc.target.Launch(launch_info, error);
     g_vsc.debugger.SetAsync(true);
   } else {
+    // Set the launch info so that run commands can access the configured
+    // launch details.
+    g_vsc.target.SetLaunchInfo(launch_info);
     g_vsc.RunLLDBCommands("Running launchCommands:", launchCommands);
     // The custom commands might have created a new target so we should use the
     // selected target after these commands are run.
     g_vsc.target = g_vsc.debugger.GetSelectedTarget();
     // Make sure the process is launched and stopped at the entry point before
     // proceeding as the the launch commands are not run using the synchronous
     // mode.
     error = g_vsc.WaitForProcessToStop(timeout_seconds);