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 #382169
mingw-build

00:05:16

passed #382167
shared-build

00:06:03

passed #382168
static-build

00:05:13