CharCodeToUnicode::mapToUnicode: Make clear the data is const

6 jobs for more_const in 9 minutes and 20 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #779601
build

00:04:07

passed #779606
build_android

00:01:56

passed #779602
build_clang_libcpp

00:04:27

passed #779605
build_clazy

00:07:59

passed #779604
build_mingw64_fedora

00:04:23

passed #779603
build_ubuntu_16_04

00:09:20