[lldb] Add QSupported key to report watchpoint types supported (#80376)

debugserver on arm64 devices can manage both Byte Address Select
watchpoints (1-8 bytes) and MASK watchpoints (8 bytes-2 gigabytes). This
adds a SupportedWatchpointTypes key to the QSupported response from
debugserver with a list of these, so lldb can take full advantage of
them when creating larger regions with a single hardware watchpoint.

Also add documentation for this, and two other lldb extensions, to the
lldb-gdb-remote.txt documentation.

Re-enable TestLargeWatchpoint.py on Darwin systems when testing with the
in-tree built debugserver. I can remove the "in-tree built debugserver"
in the future when this new key is handled by an Xcode debugserver.

1 files changed, 4 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index 866b077..bd2d3e2 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -199,6 +199,8 @@ public:
 
   std::optional<bool> GetWatchpointReportedAfter();
 
+  WatchpointHardwareFeature GetSupportedWatchpointTypes();
+
   const ArchSpec &GetHostArchitecture();
 
   std::chrono::seconds GetHostDefaultPacketTimeout();
@@ -581,6 +583,8 @@ protected:
   lldb::tid_t m_curr_tid_run = LLDB_INVALID_THREAD_ID;
 
   uint32_t m_num_supported_hardware_watchpoints = 0;
+  WatchpointHardwareFeature m_watchpoint_types =
+      eWatchpointHardwareFeatureUnknown;
   uint32_t m_low_mem_addressing_bits = 0;
   uint32_t m_high_mem_addressing_bits = 0;