cmake: always build with POSITION_INDEPENDENT_CODE

9 jobs for cmake-overhaul-3 in 4 minutes and 47 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #81244
VS2015
VS2015-32-bit

00:01:24

passed #81243
VS2015
VS2015-64-bit

00:01:35

passed #81242
VS2017
VS2017-32-bit

00:01:18

passed #81241
VS2015
VS2017-64-bit

00:01:28

passed #81238
Linux
clang-c++11

00:03:31

passed #81240
Linux
cppcheck

00:04:47

passed #81245
Linux
doc

00:00:26

passed #81237
Linux
gcc-c++11

00:03:06

passed #81239
Apple
macos-c++11

00:02:34