[lldb] add stop-at-user-entry option to process launch (#67019)

## Description
This pull request adds a new `stop-at-user-entry` option to LLDB
`process launch` command, allowing users to launch a process and pause
execution at the entry point of the program (for C-based languages,
`main` function).

## Motivation
This option provides a convenient way to begin debugging a program by
launching it and breaking at the desired entry point.

## Changes Made
- Added `stop-at-user-entry` option to `Options.td` and the
corresponding case in `CommandOptionsProcessLaunch.cpp` (short option is
'm')
- Implemented `GetUserEntryPointName` method in the Language plugins
available at the moment.
- Declared the `CreateBreakpointAtUserEntry` method in the Target API.
- Create Shell test for the command
`command-process-launch-user-entry.test`.

## Usage
`process launch --stop-at-user-entry` or `process launch -m` launches
the process and pauses execution at the entry point of the program.

1 files changed, 5 insertions, 3 deletions

diff --git a/lldb/source/Commands/CommandOptionsProcessLaunch.cpp b/lldb/source/Commands/CommandOptionsProcessLaunch.cpp
index 85ad8ff5e071..b1c13d4df79e 100644
--- a/lldb/source/Commands/CommandOptionsProcessLaunch.cpp
+++ b/lldb/source/Commands/CommandOptionsProcessLaunch.cpp
@@ -34,11 +34,15 @@ Status CommandOptionsProcessLaunch::SetOptionValue(
   Status error;
   const int short_option = g_process_launch_options[option_idx].short_option;
 
+  TargetSP target_sp =
+      execution_context ? execution_context->GetTargetSP() : TargetSP();
   switch (short_option) {
   case 's': // Stop at program entry point
     launch_info.GetFlags().Set(eLaunchFlagStopAtEntry);
     break;
-
+  case 'm': // Stop at user entry point
+    target_sp->CreateBreakpointAtUserEntry(error);
+    break;
   case 'i': // STDIN for read only
   {
     FileAction action;
@@ -89,8 +93,6 @@ Status CommandOptionsProcessLaunch::SetOptionValue(
     break;
 
   case 'a': {
-    TargetSP target_sp =
-        execution_context ? execution_context->GetTargetSP() : TargetSP();
     PlatformSP platform_sp =
         target_sp ? target_sp->GetPlatform() : PlatformSP();
     launch_info.GetArchitecture() =