[lldb] Remove -d(ebug) mode from the lldb driver (#83330)

The -d(ebug) option broke 5 years ago when I migrated the driver to
libOption. Since then, we were never check if the option is set. We were
incorrectly toggling the internal variable (m_debug_mode) based on
OPT_no_use_colors instead.

Given that the functionality doesn't seem particularly useful and nobody
noticed it has been broken for 5 years, I'm just removing the flag.

Author: JDevlieghere

lldb/test/Shell/Driver/TestHelp.test

@@ -37,8 +37,6 @@ CHECK: --arch
 CHECK: -a
 CHECK: --core
 CHECK: -c
-CHECK: --debug
-CHECK: -d
 CHECK: --editor
 CHECK: -e
 CHECK: --file

lldb/tools/driver/Driver.cpp

@@ -188,7 +188,6 @@ SBError Driver::ProcessArgs(const opt::InputArgList &args, bool &exiting) {
   if (args.hasArg(OPT_no_use_colors)) {
     m_debugger.SetUseColor(false);
     WithColor::setAutoDetectFunction(disable_color);
-    m_option_data.m_debug_mode = true;
   }
 
   if (args.hasArg(OPT_version)) {
@@ -455,16 +454,7 @@ int Driver::MainLoop() {
   // Process lldbinit files before handling any options from the command line.
   SBCommandReturnObject result;
   sb_interpreter.SourceInitFileInGlobalDirectory(result);
-  if (m_option_data.m_debug_mode) {
-    result.PutError(m_debugger.GetErrorFile());
-    result.PutOutput(m_debugger.GetOutputFile());
-  }
-
   sb_interpreter.SourceInitFileInHomeDirectory(result, m_option_data.m_repl);
-  if (m_option_data.m_debug_mode) {
-    result.PutError(m_debugger.GetErrorFile());
-    result.PutOutput(m_debugger.GetOutputFile());
-  }
 
   // Source the local .lldbinit file if it exists and we're allowed to source.
   // Here we want to always print the return object because it contains the
@@ -536,11 +526,6 @@ int Driver::MainLoop() {
                             "or -s) are ignored in REPL mode.\n";
   }
 
-  if (m_option_data.m_debug_mode) {
-    result.PutError(m_debugger.GetErrorFile());
-    result.PutOutput(m_debugger.GetOutputFile());
-  }
-
   const bool handle_events = true;
   const bool spawn_thread = false;
 

lldb/tools/driver/Driver.h

@@ -75,7 +75,6 @@ class Driver : public lldb::SBBroadcaster {
     std::vector<InitialCmdEntry> m_after_file_commands;
     std::vector<InitialCmdEntry> m_after_crash_commands;
 
-    bool m_debug_mode = false;
     bool m_source_quietly = false;
     bool m_print_version = false;
     bool m_print_python_path = false;