fix assumption about std handles in os2/file.odin

core/os/os2/file.odin

@@ -45,11 +45,9 @@ O_TRUNC   :: File_Flags{.Trunc}
 O_SPARSE  :: File_Flags{.Sparse}
 O_CLOEXEC :: File_Flags{.Close_On_Exec}
 
-
-stdin:  ^File = &_stdin
-stdout: ^File = &_stdout
-stderr: ^File = &_stderr
-
+stdin:  ^File = nil // OS-Specific
+stdout: ^File = nil // OS-Specific
+stderr: ^File = nil // OS-Specific
 
 @(require_results)
 create :: proc(name: string) -> (^File, Error) {