#1664: Skip some too strict checks which I don't yet know how to cove…

…r by tests (and not required)

src/psyclone/transformations.py

@@ -2321,21 +2321,6 @@ def validate(self, sched, options=None):
             raise TransformationError("Schedule already has an OpenACC data "
                                       "region - cannot add an enter data.")
 
-        # do not has mixed async
-        if options == None:
-            options = {}
-        async_queue = options.get('async_queue', False)
-        if async_queue:
-            directive_cls = (ACCKernelsDirective, ACCParallelDirective)
-            for directive in sched.walk(directive_cls):
-                if directive.async_queue and directive.async_queue != async_queue:
-                    raise TransformationError(f"Tried to apply async() while another one is used internally \
-                                               with different queue ({async_queue} != {directive.async_queue}) !")
-            directive = sched.ancestor(directive_cls)
-            if directive and directive.async_queue and directive.async_queue != async_queue:
-                raise TransformationError(f"Tried to apply async() while another one is used in ancestor \
-                                            with different queue ({async_queue} != {directive.async_queue}) !")
-
 
 class ACCRoutineTrans(Transformation):
     '''