[python, tests] Disable Clang Python tests on SPARC

[python, tests] Disable Clang Python tests on SPARC

Running `make check-all` fails on Solaris 11/SPARC since the clang python
tests FAIL:

  ............................
  ======================================================================
  FAIL: test_extent (tests.cindex.test_location.TestLocation)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "tests/cindex/test_location.py", line 87, in test_extent
      self.assert_location(one.extent.start,line=1,column=1,offset=0)
    File "tests/cindex/test_location.py", line 22, in assert_location
      self.assertEqual(loc.column, column)
  AssertionError: 5 != 1

  ======================================================================
  FAIL: test_get_children (tests.cindex.test_cursor.TestCursor)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "tests/cindex/test_cursor.py", line 70, in test_get_children
      self.assertEqual(tu_nodes[0].is_definition(), True)
  AssertionError: False != True

  ----------------------------------------------------------------------
  Ran 126 tests in 2.123s

  FAILED (failures=2, skipped=6)

Unfortunately, this aborts the rest of `make check-all`, even with `-k`, so
this patch disables the test as is already done on a couple of other
targets.

This allowed the `sparc-sun-solaris2.11` test to finish.

Differential Revision: https://reviews.llvm.org/D60046

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357917 91177308-0d34-0410-b5e6-96231b3b80d8