-add breakpoint statement to ease with debugging, closes #3165

modules/gdscript/gd_parser.h

@@ -54,6 +54,7 @@ public:
 			TYPE_CONTROL_FLOW,
 			TYPE_LOCAL_VAR,
 			TYPE_ASSERT,
+			TYPE_BREAKPOINT,
 			TYPE_NEWLINE,
 		};
 
@@ -276,6 +277,10 @@ public:
 		AssertNode() { type=TYPE_ASSERT; }
 	};
 
+	struct BreakpointNode : public Node {
+		BreakpointNode() { type=TYPE_BREAKPOINT; }
+	};
+
 	struct NewLineNode : public Node {
 		NewLineNode() { type=TYPE_NEWLINE; }
 	};