Implement DAP stepOut request

This implements the DAP "stepOut" request.

gdb/python/lib/gdb/dap/next.py

@@ -44,6 +44,12 @@ def stepIn(*, threadId, granularity="statement", **args):
     send_gdb(ExecutionInvoker(cmd, StopKinds.STEP))
 
 
+@request("stepOut")
+def step_out(*, threadId):
+    _handle_thread_step(threadId)
+    send_gdb(ExecutionInvoker("finish", StopKinds.STEP))
+
+
 @request("continue")
 def continue_request(**args):
     send_gdb(ExecutionInvoker("continue", None))

gdb/testsuite/gdb.dap/basic-dap.c

@@ -35,10 +35,18 @@ address_breakpoint_here ()
 {
 }
 
-int main ()
+int
+line_breakpoint_here ()
 {
   do_not_stop_here ();
   function_breakpoint_here ();
   address_breakpoint_here ();
   return 0;			/* BREAK */
 }
+
+
+int
+main ()
+{
+  return line_breakpoint_here ();
+}

gdb/testsuite/gdb.dap/basic-dap.exp

@@ -146,6 +146,11 @@ dap_wait_for_event_and_check "stopped at line breakpoint" stopped \
     "body reason" breakpoint \
     "body hitBreakpointIds" $line_bpno
 
+dap_check_request_and_response "return from function" stepOut \
+    {o threadId [i 1]}
+dap_wait_for_event_and_check "stopped after return" stopped \
+    "body reason" step
+
 set obj [dap_check_request_and_response "evaluate global in main" \
 	     evaluate {o expression [s global_variable]}]
 dap_match_values "global value in main" [lindex $obj 0] \