Use new syntax for super hash calls

This fixes the following error with pypy 5.6.0 (2.7.12)

File "../pygccxml/pygccxml/declarations/calldef.py", line 233, in __hash__
    hash(self.return_type) ^
TypeError: unbound method __hash__() must be called with super instance as first argument (got free_function_t instance instead)

The cpython implementation was OK with this, though the syntax is dubious.
The new way of writing this is better as it clearly defines what is called
in the class tree.

Some of the calls may even be unnecessary, but I am leaving
them as-is for the moment.

Cherry-picked from the develop branch

Author: iMichka

pygccxml/declarations/calldef.py

@@ -264,12 +264,12 @@ def __eq__(self, other):
 
     def __hash__(self):
         if "GCC" in utils.xml_generator:
-            return (super.__hash__(self) ^
+            return (super(calldef_t, self).__hash__() ^
                     hash(self.return_type) ^
                     hash(self.demangled_name))
         elif "CastXML" in utils.xml_generator:
             # No demangled name with castxml. Use the normal name.
-            return (super.__hash__(self) ^
+            return (super(calldef_t, self).__hash__() ^
                     hash(self.return_type) ^
                     hash(self.name))
 

pygccxml/declarations/calldef_members.py

@@ -64,7 +64,7 @@ def __eq__(self, other):
             and self.has_const == other.has_const
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(member_calldef_t, self).__hash__()
 
     @property
     def virtuality(self):

pygccxml/declarations/cpptypes.py

@@ -935,7 +935,7 @@ def __eq__(self, other):
             and self.has_mutable == other.has_mutable
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(type_qualifiers_t, self).__hash__()
 
     def __ne__(self, other):
         return not self.__eq__(other)

pygccxml/declarations/enumeration.py

@@ -47,7 +47,7 @@ def __eq__(self, other):
         return self.values == other.values
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(enumeration_t, self).__hash__(self)
 
     def _get__cmp__items(self):
         """implementation details"""

pygccxml/declarations/scopedef.py

@@ -228,7 +228,7 @@ def __eq__(self, other):
         # return self_decls == other_decls
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(scopedef_t, self).__hash__()
 
     def _get_declarations_impl(self):
         raise NotImplementedError()

pygccxml/declarations/typedef.py

@@ -44,7 +44,7 @@ def __eq__(self, other):
         return self.decl_type == other.decl_type
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(typedef_t, self).__hash__(self)
 
     @property
     def type(self):

pygccxml/declarations/variable.py

@@ -61,7 +61,7 @@ def __eq__(self, other):
             and self.bits == other.bits
 
     def __hash__(self):
-        return super.__hash__(self)
+        return super(variable_t, self).__hash__()
 
     @property
     def type(self):