Fix obtaining real path from pre-defined names for Win32

Fixes fontconfig/fontconfig#166
3 jobs for issue/166 in 15 minutes (queued for 3 minutes and 24 seconds)
Status Job ID Name Coverage
  Build
passed mingw-build #382169

00:05:16

passed shared-build #382167

00:06:03

passed static-build #382168

00:05:13