[LNT] Python 3 support: Get next element with next builtin

[thopre]

Summary

Use next() builtin rather than the .next() method to retrieve the next
element of an iterator since the latter does not exist in Python 3.
next() builtin was introduced in Python 2.6. This was produced by
running futurize's stage1 libfuturize.fixes.fix_next_call.

[hubert.reinterpretcast]

LGTM.

lnt/testing/profile/profilev2impl.py

class Functions(Section):
 
     def getCodeForFunction(self, fname):
         f = self.functions[fname]
         counter_gen = self.line_counters \
             .extractForFunction(fname, f['counters'].keys())
         address_gen = self.line_addresses.extractForFunction(fname)
         text_gen = self.line_text.extractForFunction(fname)
         for n in xrange(f['length']):
-            yield (counter_gen.next(), address_gen.next(), text_gen.next())
+            yield (next(counter_gen), next(address_gen), next(text_gen))
 
     def copy(self, counter_name_pool, line_counters,
              line_addresses, line_text):
         new = copy.copy(self)
         new.counter_name_pool = counter_name_pool
         new.line_counters = line_counters
         new.line_addresses = line_addresses
         new.line_text = line_text

lnt/tests/nt.py

else:
         if config.test_jit:
             append_to_sample_keys((True, 'jit.exec', 'JIT', 'time'))
 
     # Load the report file.
     report_file = open(report_path, 'rb')
     reader_it = iter(csv.reader(report_file))
 
     # Get the header.
-    header = reader_it.next()
+    header = next(reader_it)
     if header[0] != 'Program':
         fatal('unexpected report file, missing header')
 
     # Verify we have the keys we expect.
     if 'Program' not in header:
         fatal('missing key %r in report header' % 'Program')
     for item in sample_keys:
         required = item[0]