Opencl datahandling

Since the target_dh_refactoring was never merged, we decided to do the refactoring at smaller steps and recover the original OpenCL datahandling PR.

Refactoring to merge target and backend can be done later.

pystencils/interpolation_astnodes.py

@@ -142,8 +142,8 @@ class NearestNeightborInterpolator(Interpolator):
 
 
 class InterpolatorAccess(TypedSymbol):
-    def __new__(cls, field, offsets, *args, **kwargs):
-        obj = TextureAccess.__xnew_cached_(cls, field, offsets, *args, **kwargs)
+    def __new__(cls, field, *offsets, **kwargs):
+        obj = TextureAccess.__xnew_cached_(cls, field, *offsets, **kwargs)
         return obj
 
     def __new_stage2__(self, symbol, *offsets):
@@ -287,6 +287,9 @@ class InterpolatorAccess(TypedSymbol):
     # noinspection SpellCheckingInspection
     __xnew_cached_ = staticmethod(cacheit(__new_stage2__))
 
+    def __getnewargs__(self):
+        return tuple(self.symbol, *self.offsets)
+
 ##########################################################################################
 # GPU-specific fast specializations (for precision GPUs can also use above nodes/symbols #
 ##########################################################################################
@@ -362,8 +365,8 @@ class TextureCachedField:
 
 
 class TextureAccess(InterpolatorAccess):
-    def __new__(cls, texture_symbol, offsets, *args, **kwargs):
-        obj = TextureAccess.__xnew_cached_(cls, texture_symbol, offsets, *args, **kwargs)
+    def __new__(cls, texture_symbol, *offsets, **kwargs):
+        obj = TextureAccess.__xnew_cached_(cls, texture_symbol, *offsets, **kwargs)
         return obj
 
     def __new_stage2__(self, symbol, *offsets):