Enable range iterators on MSVC.

MSVC does not define __cplusplus as >=201103 yet.
An older version of MSVC is probably sufficient, but I can't test that.
9 jobs from rangeiter-msvc in 3 minutes and 38 seconds
Status Job ID Name Coverage
  Test
passed #26923
VS2013
VS2013-32-bit

00:00:51

passed #26922
VS2013
VS2013-64-bit

00:00:58

passed #26921
VS2015
VS2015-32-bit

00:01:08

passed #26920
VS2015
VS2015-64-bit

00:01:22

passed #26917
Linux
clang-c++11

00:03:19

passed #26919
Linux
cppcheck

00:00:41

passed #26924
Linux
doc

00:00:19

passed #26916
Linux
gcc-c++11

00:03:38

passed #26918
Apple
macos-c++11

00:01:29