Use GetFileAttributesW for checking file existence on Windows

[YYF233333]

Partially address #78645. (solved by #101435)

Help to address #100109.

We are using _wfsopen in FileAccessWindows::file_exists which opens a file just to check it is there. Use GetFileAttributesW makes this function a lot faster. In MRP of #78645 reduce the lag by about a half (measured by eyes, not that accurate).

I used to complain that file operations on Windows were very slow. My apologies for wrongly blaming you, Windows :)

[YYF233333]

I see GLOBAL_LOCK_FUNCTION in DirAccessWindows::file_exists which uses GetFileAttributesW, so GetFileAttributesW is not as thread safe as _wfsopen? Shall I add it?

[kiroxas]

Reading metadata will be faster than opening the file, for sure.

[YYF233333]

Tested and this do help address #100109.

master

1.gd load: 1.22ms
2.gd load: 1.46ms
3.gd load: 1.57ms
......
64.gd load: 14.75ms
65.gd load: 14.87ms
66.gd load: 15.11ms
67.gd load: 15.68ms
68.gd load: 16.14ms
69.gd load: 15.91ms

This PR

1.gd load: 1.12ms
2.gd load: 1.15ms
3.gd load: 1.34ms
......
65.gd load: 12.17ms
66.gd load: 12.27ms
67.gd load: 12.61ms
68.gd load: 12.77ms
69.gd load: 12.88ms

[bruvzg]

DirAccessWindows use the same function, so I do not see any reason to open the file here.

[akien-mga]

Thanks!