let loopy manage determinants st vectorization is possible

python/dune/codegen/pdelab/tensors.py

@@ -17,7 +17,7 @@ import itertools as it
 
 
 def define_determinant(name, matrix, shape, visitor):
-    temporary_variable(name)
+    temporary_variable(name, managed=True)
 
     assert len(shape) == 2 and shape[0] == shape[1]
     dim = shape[0]
@@ -46,7 +46,7 @@ def define_determinant(name, matrix, shape, visitor):
 def define_determinant_inverse(name, matrix, shape, visitor):
     det = name_determinant(matrix, shape, visitor)
 
-    temporary_variable(name)
+    temporary_variable(name, managed=True)
 
     instruction(expression=prim.Quotient(1, prim.Variable(det)),
                 assignee=prim.Variable(name),