class_docstr: Remove implicit tuple -> variable conversion.
  
  >>> import gast as ast
  >>> from pythran import passmanager, backend
  >>> node = ast.parse("def foo(): a=(1,2.) ; i,j = a")
  >>> pm = passmanager.PassManager("test")
  >>> _, node = pm.apply(NormalizeTuples, node)
  >>> print(pm.dump(backend.Python, node))
  def foo():
      a = (1, 2.0)
      i = a[0]
      j = a[1]
code: def visit_AnyComp(self, node, *fields):
      for field in fields:
          setattr(node, field, self.visit(getattr(node, field)))
      generators = [
          self.visit(generator) for generator in node.generators
      ]
      nnode = node
      for i, g in enumerate(generators):
          if isinstance(g, tuple):
              gtarget = "{0}{1}".format(g[0], i)
              nnode.generators[i].target = ast.Name(
                  gtarget, nnode.generators[i].target.ctx, None, None
              )
              nnode = ConvertToTuple(gtarget, g[1]).visit(nnode)
              self.update = True
      for field in fields:
          setattr(node, field, getattr(nnode, field))
      node.generators = nnode.generators
      return node
  
imports: from pythran.analyses import Identifiers
  from pythran.passmanager import Transformation
  import gast
  from functools import reduce
  from collections import OrderedDict
  from copy import deepcopy
label_desc: Use image node_id 5 for calling the NormalizeTuples obj's underlying member method code with example usage: obj.visit_AnyComp(node) and returns: node