[lldb] Use target.GetLaunchInfo() instead of creating an empty one.

Update tests that were creating an empty LaunchInfo instead of using the
one coming from the target. This ensures target properties are honored.

lldb/test/API/python_api/process/TestProcessAPI.py

@@ -339,7 +339,7 @@ class ProcessAPITestCase(TestBase):
         self.assertTrue(target, VALID_TARGET)
 
         # Launch the process and stop at the entry point.
-        launch_info = lldb.SBLaunchInfo(None)
+        launch_info = target.GetLaunchInfo()
         launch_info.SetWorkingDirectory(self.get_process_working_directory())
         launch_flags = launch_info.GetLaunchFlags()
         launch_flags |= lldb.eLaunchFlagStopAtEntry

lldb/test/API/python_api/process/io/TestProcessIO.py

@@ -135,7 +135,7 @@ class ProcessIOTestCase(TestBase):
     def create_target(self):
         '''Create the target and launch info that will be used by all tests'''
         self.target = self.dbg.CreateTarget(self.exe)
-        self.launch_info = lldb.SBLaunchInfo([self.exe])
+        self.launch_info = self.target.GetLaunchInfo()
         self.launch_info.SetWorkingDirectory(
             self.get_process_working_directory())