[tree-ssa] Failure with contained functions

[Paul Brook]

The following program miscompiles on the tree-ssa branch at -O1 and -O2.

int main()
{
  int a;
  void test(int i)
    {
      a = i;
    };
  a = 0;
  test (42);
  if (a != 42)
    abort ();
  return 0;
}

It looks like the ssa pass doesn't know about contained functions, and 
misses the redefinition of a inside the contained function.

Paul Brook