Add zh-CHT parent lcid handling. Fixes #11375
Fix quoting of some date time patters. Fixes #11363
Export a few functions needed by llvm.
update cecil rev.

We cannot fully update cecil to the latest master which seems to break
some existing code, so use specific branch so far.
Populate AbbreviatedMonthNames values. Fixes #11361
Set invariant DateTimeFormatInfo for all invariant format specifiers. Fixes #11364
Update number separators for mexican and similar locales. Fixes #8084
Set errno to 0 before calling readdir in Syscall.readdir().

This will allow the caller to distinguish between errors and end-of-directory.
Return null when null was passed to Marshal.PtrToStructure () instead of throwing an exception. Fixes #11417.
Remove a redundant null check.
[corlib] Marshal: fine-tune the pointer Read/Write operations.

This patch reworks the Marshal's Read and Write pointer operations
to avoid performing a modulo operation to choose the fast path, as
in some platforms the modulo operation is implemented as a C subroutine.

Instead we use bit operations which always run in constant time.

It also avoids the IntPtr.XXX method calls, factors out "unsafe", only
ever performs one IntPtr->pointer conversion, and makes the source
code uniform.
Export a few more symbols for LLVM.
Add various methods and flags to Syscall

    * Add OpenFlags.O_CLOEXEC and OpenFlags.O_PATH

    * Add AtFlags for AT_* values

    * Add fdopendir, mkdtemp, futimens

    * Add readv, writev, preadv, pwritev

    * Add *at methods: openat, renameat, fchmodat, fstatat, utimensat,
      mkdirat, mknodat, mkfifoat, faccessat, fchownat, linkat, readlinkat,
      symlinkat, unlinkat

    * Add constants AT_FDCWD, UTIME_NOW, UTIME_OMIT
Merge pull request #221 from steffen-kiess/master

Add various methods and flags to Syscall
Fix sdb asserts when seq-points are not found for a method because its assembly was AOTed without the 'soft-debug' option. Fixes #11435.