LDC 1.27.0-beta2

[workman]

On Thursday, 24 June 2021 at 23:14:26 UTC, kinke wrote:
> Glad to announce the second beta for LDC 1.27. Some noteworthy 
> changes since beta1:
>
> * Frontend and druntime/Phobos upgraded to yesterday's DMD 
> stable.
> * Windows DLL support: some fixes/tweaks and a new -dllimport 
> option for greater flexibility.
> * Prebuilt Linux and Mac packages can show significant compiler 
> performance increases due to newly employing the mimalloc 
> allocator.
> * Important fixes for -linkonce-templates, DWARF v5 (e.g. with 
> linked-in C[++] parts compiled with gcc 11) and bundled dub 
> supporting somewhat longer paths on Windows.
>
> Full release log and downloads: 
> https://github.com/ldc-developers/ldc/releases/tag/v1.27.0-beta2
>
> Please help test, and thanks to all contributors & sponsors!

undefined symbol __fieldPostblit and __postblit cause link error 
only with LTO enabled for windows mingw target.

There is more undefined symbols for LDC 1.27 compare to 1.26. My 
code not changed and they used to work with old version ldc.

without LTO all work fine, old LDC link with -flto and -O fix the 
missing symbol,  but 1.26 && 1.27 not work anymore.