add missing error code handling on Windows

lib/std/fs.zig

@@ -841,6 +841,7 @@ pub const Dir = struct {
             w.STATUS.ACCESS_DENIED => return error.AccessDenied,
             w.STATUS.PIPE_BUSY => return error.PipeBusy,
             w.STATUS.OBJECT_PATH_SYNTAX_BAD => unreachable,
+            w.STATUS.OBJECT_NAME_COLLISION => return error.PathAlreadyExists,
             else => return w.unexpectedStatus(rc),
         }
     }

lib/std/fs/file.zig

@@ -228,6 +228,7 @@ pub const File = struct {
                 windows.STATUS.SUCCESS => {},
                 windows.STATUS.BUFFER_OVERFLOW => {},
                 windows.STATUS.INVALID_PARAMETER => unreachable,
+                windows.STATUS.ACCESS_DENIED => return error.AccessDenied,
                 else => return windows.unexpectedStatus(rc),
             }
             return Stat{

lib/std/io/test.zig

@@ -634,7 +634,7 @@ test "File seek ops" {
 
 test "updateTimes" {
     const tmp_file_name = "just_a_temporary_file.txt";
-    var file = try fs.cwd().createFile(tmp_file_name, .{});
+    var file = try fs.cwd().createFile(tmp_file_name, .{ .read = true });
     defer {
         file.close();
         std.fs.cwd().deleteFile(tmp_file_name) catch {};

lib/std/os.zig

@@ -2028,7 +2028,10 @@ pub fn waitpid(pid: i32, flags: u32) u32 {
     }
 }
 
-pub const FStatError = error{SystemResources} || UnexpectedError;
+pub const FStatError = error{
+    SystemResources,
+    AccessDenied,
+} || UnexpectedError;
 
 pub fn fstat(fd: fd_t) FStatError!Stat {
     var stat: Stat = undefined;
@@ -2038,6 +2041,7 @@ pub fn fstat(fd: fd_t) FStatError!Stat {
             EINVAL => unreachable,
             EBADF => unreachable, // Always a race condition.
             ENOMEM => return error.SystemResources,
+            EACCES => return error.AccessDenied,
             else => |err| return unexpectedErrno(err),
         }
     }
@@ -2047,6 +2051,7 @@ pub fn fstat(fd: fd_t) FStatError!Stat {
         EINVAL => unreachable,
         EBADF => unreachable, // Always a race condition.
         ENOMEM => return error.SystemResources,
+        EACCES => return error.AccessDenied,
         else => |err| return unexpectedErrno(err),
     }
 }