Closes https://github.com/ziglang/zig/issues/19284
As of 9f2cb920c055bc990cc9d593b8dc9eaa450d07b9 configuring the globalcache directory to a relative path causes errors of the following formwhen cross compiling to windows-gnu.`error: unable to generate DLL import .lib file for kernel32: FileNotFound`
The issue occurred because the def_final_path included the globalcache path as a prefix and later on the def_final_file was createdusing that path with the global cache directory handle.