[lldb/test] Fix PExpect.launch issue when disabling color support

[mib]

Summary

This patch should fix a bug in PExpect.launch that happened when color
support is not enabled.

In that case, we need to add the --no-use-colors flag to lldb's launch
argument list. However, previously, each character to the string was
appended separately to the args list. This patch solves that by adding
the whole string to the list.

This should fix the TestIOHandlerResize failure on GreenDragon.

Signed-off-by: Med Ismail Bennani <[e-mail]>

lldb/packages/Python/lldbsuite/test/lldbpexpect.py

def launch(self, executable=None, extra_args=None, timeout=60,
         logfile = getattr(sys.stdout, 'buffer',
                             sys.stdout) if self.TraceOn() else None
 
         args = []
         if run_under is not None:
             args += run_under
         args += [lldbtest_config.lldbExec, '--no-lldbinit']
         if not use_colors:
-            args += '--no-use-colors'
+            args.append('--no-use-colors')
         for cmd in self.setUpCommands():
             if "use-color false" in cmd and use_colors:
                 continue
             args += ['-O', cmd]
         if executable is not None:
             args += ['--file', executable]
         if extra_args is not None:
             args.extend(extra_args)