std.io: move getStdIn, getStdOut, getStdErr functions to fs.File
preparing to rearrange std.io namespace into an interface
how to upgrade:
std.io.getStdIn() -> std.fs.File.stdin()
std.io.getStdOut() -> std.fs.File.stdout()
std.io.getStdErr() -> std.fs.File.stderr()
0b3f0124dcAndrew Kelley committed on 7/8/2025, 5:43:51 AMparent7c42517