gbasename: Include stdlib for free

fixes macos build
6 jobs for master in 7 minutes and 43 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #106912
build

00:03:15

passed #106917
build_android

00:01:14

passed #106913
build_clang_libcpp

00:04:42

passed #106916
build_clazy

00:04:28

passed #106914
build_gcc_49

00:07:32

passed #106915
build_mingw64_fedora

00:07:42