[lldb] Clear thread-creation breakpoints in ProcessGDBRemote::Clear

Currently, these breakpoints are being accumulated every time a new
process if created (e.g. through a `run`). Depending on the
circumstances, the old breakpoints are even left enabled, interfering
with subsequent processes. This is addressed by removing the breakpoints
in ProcessGDBRemote::Clear

Note that these breakpoints are more of a PlatformDarwin thing, so in
the future we should look into moving them there.

Author: felipepiovezan

lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp

@@ -3410,6 +3410,9 @@ Status ProcessGDBRemote::DisableWatchpoint(WatchpointSP wp_sp, bool notify) {
 void ProcessGDBRemote::Clear() {
   m_thread_list_real.Clear();
   m_thread_list.Clear();
+  if (m_thread_create_bp_sp)
+    if (TargetSP target_sp = m_target_wp.lock())
+      target_sp->RemoveBreakpointByID(m_thread_create_bp_sp->GetID());
 }
 
 Status ProcessGDBRemote::DoSignal(int signo) {

lldb/test/API/macosx/thread_start_bps/TestBreakpointsThreadInit.py

@@ -35,3 +35,23 @@ def test_internal_bps_resolved(self):
         for bp in bps:
             num_resolved += bp.GetNumResolvedLocations()
         self.assertGreater(num_resolved, 0)
+
+    @skipUnlessDarwin
+    def test_internal_bps_deleted_on_relaunch(self):
+        self.build()
+
+        source_file = lldb.SBFileSpec("main.c")
+        target, process, thread, bkpt = lldbutil.run_to_source_breakpoint(
+            self, "initial hello", source_file
+        )
+
+        self.runCmd("break list --internal")
+        output = self.res.GetOutput()
+        self.assertEqual(output.count("thread-creation"), 1)
+
+        process.Kill()
+        self.runCmd("run", RUN_SUCCEEDED)
+
+        self.runCmd("break list --internal")
+        output = self.res.GetOutput()
+        self.assertEqual(output.count("thread-creation"), 1)