[lldb] Fix CommandInterpreter::DidProcessStopAbnormally() with multiple threads

If a process has multiple threads, the thread with the stop
info might not be the first one in the thread list.

On Windows, under certain circumstances, processes seem to have
one or more extra threads that haven't been launched by the
executable itself, waiting in NtWaitForWorkViaWorkerFactory. If the
main (stopped) thread isn't the first one in the list (the order
seems nondeterministic), DidProcessStopAbnormally() would return
false prematurely, instead of inspecting later threads.

The main observable effect of DidProcessStopAbnormally() erroneously
returning false, is when running lldb with multiple "-o" parameters
to specify multiple commands to execute on the command line.

After an abnormal stop, lldb would stop executing "-o" parameters
and execute "-k" parameters instead - but due to this issue, it
would instead keep executing "-o" parameters as if there was no
abnormal stop. (If multiple parameters are specified via a script
file via the "-s" option, all of the commands in that file are
executed regardless of whether there's an abnormal stop inbetween.)

Differential Revision: https://reviews.llvm.org/D134037

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -2471,8 +2471,12 @@ bool CommandInterpreter::DidProcessStopAbnormally() const {
 
   for (const auto &thread_sp : process_sp->GetThreadList().Threads()) {
     StopInfoSP stop_info = thread_sp->GetStopInfo();
-    if (!stop_info)
-      return false;
+    if (!stop_info) {
+      // If there's no stop_info, keep iterating through the other threads;
+      // it's enough that any thread has got a stop_info that indicates
+      // an abnormal stop, to consider the process to be stopped abnormally.
+      continue;
+    }
 
     const StopReason reason = stop_info->GetStopReason();
     if (reason == eStopReasonException ||

lldb/test/Shell/Driver/CommandOnCrashMultiThreaded.test

@@ -0,0 +1,5 @@
+# REQUIRES: native && (target-x86 || target-x86_64)
+# RUN: %clangxx_host %p/Inputs/CommandOnCrashMultiThreaded.cpp -o %t -pthread
+# RUN: %lldb -b -o "process launch" -k "process continue" -k "exit" %t | FileCheck %s
+
+# CHECK: Process {{[0-9]+}} exited with status = 0

lldb/test/Shell/Driver/Inputs/CommandOnCrashMultiThreaded.cpp

@@ -0,0 +1,13 @@
+#include <thread>
+
+void t_func() {
+  asm volatile(
+    "int3\n\t"
+  );
+}
+
+int main() {
+  std::thread t(t_func);
+  t.join();
+  return 0;
+}