Test Mock GPU sends expected packets

[imyixinw]

We write a unit test to check that all the correct messages are getting sent in between the Mock GPU server and the native server. It ensures that packets are sent and received with the expected content, validating key plugin behaviors such as breakpoint disabling and library loading flags.

Testing

$ ./bin/llvm-lit /lldb/test/API/gpu/mock/packets/TestPacketsMockGpuPlugin.py -v
-- Testing: 1 tests, 1 workers --
PASS: lldb-api :: gpu/mock/packets/TestPacketsMockGpuPlugin.py (1 of 1)

Testing Time: 1.03s

Total Discovered Tests: 1
  Passed: 1 (100.00%)