[Python] Implement __next__ for value_iter

[JDevlieghere]

Summary

Python 3 iteration calls the next() method instead of next() and
value_iter only implemented the Python 2 version.

[davide]

LGTM

lldb/trunk/packages/Python/lldbsuite/test/python_api/value/TestValueAPI.py

def test(self):
         self.assertFalse(lldb.value(frame0.FindVariable('bogus')))
         self.assertTrue(lldb.value(frame0.FindVariable('uinthex')))
 
         self.assertTrue(int(lldb.value(frame0.FindVariable('uinthex')))
                         == 3768803088, 'uinthex == 3768803088')
         self.assertTrue(int(lldb.value(frame0.FindVariable('sinthex')))
                         == -526164208, 'sinthex == -526164208')
 
+        # Check value_iter works correctly.
+        for v in [
+                lldb.value(frame0.FindVariable('uinthex')),
+                lldb.value(frame0.FindVariable('sinthex'))
+        ]:
+            self.assertTrue(v)
+
         self.assertTrue(
             frame0.FindVariable('uinthex').GetValueAsUnsigned() == 3768803088,
             'unsigned uinthex == 3768803088')
         self.assertTrue(
             frame0.FindVariable('sinthex').GetValueAsUnsigned() == 3768803088,
             'unsigned sinthex == 3768803088')
 
         self.assertTrue(
             frame0.FindVariable('uinthex').GetValueAsSigned() == -
             526164208,
             'signed uinthex == -526164208')
         self.assertTrue(
             frame0.FindVariable('sinthex').GetValueAsSigned() == -
             526164208,
             'signed sinthex == -526164208')

lldb/trunk/scripts/Python/python-extensions.swig

def __init__(self, file, line, col):
         self.file = file
         self.line = line
         self.col = col
 
 class value_iter(object):
     def __iter__(self):
         return self
 
-    def next(self):
+    def __next__(self):
         if self.index >= self.length:
             raise StopIteration()
         child_sbvalue = self.sbvalue.GetChildAtIndex(self.index)
         self.index += 1
         return value(child_sbvalue)
 
+    def next(self):
+        return self.__next__()
+
     def __init__(self,value):
         self.index = 0
         self.sbvalue = value
         if type(self.sbvalue) is value:
             self.sbvalue = self.sbvalue.sbvalue
         self.length = self.sbvalue.GetNumChildren()
 
 class value(object):