make all negative handles invalid, not just -1

23 jobs for invalid_handles in 72 minutes and 47 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #13545
VS2013
VS2013-32-bit-shared-apps

00:04:54

passed #13546
VS2013
VS2013-32-bit-shared-no-apps

00:03:57

passed #13549
VS2013
VS2013-32-bit-static-apps

00:05:42

passed #13550
VS2013
VS2013-32-bit-static-no-apps

00:03:43

passed #13543
VS2013
VS2013-64-bit-shared-apps

00:05:32

passed #13544
VS2013
VS2013-64-bit-shared-no-apps

00:04:22

passed #13547
VS2013
VS2013-64-bit-static-apps

00:05:29

passed #13548
VS2013
VS2013-64-bit-static-no-apps

00:04:37

passed #13537
VS2015
VS2015-32-bit-shared-apps

00:06:17

passed #13538
VS2015
VS2015-32-bit-shared-no-apps

00:05:23

passed #13541
VS2015
VS2015-32-bit-static-apps

00:06:06

passed #13542
VS2015
VS2015-32-bit-static-no-apps

00:05:21

passed #13535
VS2015
VS2015-64-bit-shared-apps

00:07:28

passed #13536
VS2015
VS2015-64-bit-shared-no-apps

00:06:21

passed #13539
VS2015
VS2015-64-bit-static-apps

00:07:04

passed #13540
VS2015
VS2015-64-bit-static-no-apps

00:06:13

passed #13529
Linux
clang-c++11

00:21:24

passed #13531
Linux
clang-c++98

00:16:46

passed #13534
Linux
cppcheck

00:00:26

passed #13528
Linux
gcc-c++11

00:04:29

passed #13530
Linux
gcc-c++98

00:24:35

passed #13532
Apple
macos-c++11

00:16:27

passed #13533
Apple
macos-c++98

00:15:33