add toHash() to Typedef
add unittest for Typedef.toHash
add unittest for Typedef.toHash
some update
datetime scope imports

more scope imports

restore std.time global import

check scope imports

update windows unitises
use auto return in std.datetime
add local import
fix import
Merge pull request #2689 from WalterBright/toauto

[blocker fix]: use auto return in std.datetime
issue 13717

https://issues.dlang.org/show_bug.cgi?id=13717
Merge pull request #2692 from 9il/issue13717

fix issue 13717
std.windows.syserror: Fix doc build error
fix LockingTextReader: issues 13686 and 12320

Issue 13686 (Reading unicode string with readf ("%s") produces a wrong
string) is fixed by reading all chars of a multibyte sequence and decoding.
Before, each char was mistaken for a dchar.

Issue 12320 (std.stdio.LockingTextReader populates .front in .empty) is
fixed by moving the work from empty to popFront.
fix scope import for Windows
std.internal.cstring: clean imports
scope buffer: clean imports
std.bitmanip: clean imports
Merge pull request #2695 from 9il/sb

scope buffer: clean imports
Merge pull request #2696 from 9il/bm

std.bitmanip: clean imports
Merge pull request #2694 from 9il/cstring

std.internal.cstring: clean imports