C#

TranslateMessage function (winuser.h) | Microsoft Docs[^]:

The character messages are posted to the calling thread's message queue, to be read the next time the thread calls the GetMessage or PeekMessage function.

<PlatformTarget>AnyCPU</PlatformTarget>

Bernhard Hiller wrote:

But compiling for 64bit only could allow for more compiler optimizations (or am I mistaken?), so I'd prefer to create 64bit executables.

• Drop 32bit versions of dependencies and drop the release that uses them. Sounds like that's the plan.
• Write code that explicitly assumes pointers are 8 bytes (doesn't come up a lot in C# obviously, but you can do it).
• In 32bit mode, FP math gets done with x87 instructions, occasionally this required some workarounds to deal with 80bit/64bit precision mismatches, all of that nonsense can be removed. Most projects didn't bother with this in the first place.
• Boldly using System.Numerics.Vectors all over the place, which is fast (well, some parts of it are fast, definitely double check) in 64bit mode but worse than pointless in 32bit mode.
• Using things from System.Runtime.Intrinsics with X64 in the name, such as System.Runtime.Intrinsics.X86.Sse.X64, without checking IsSupported and without fallback.

var x = list.GroupBy(g => g.Key).Select(grp => grp.Skip(1)).SelectMany(i => i);

var x = list.GroupBy(g => g.Key).Select(grp =>
    grp.Count() == 1 
       ? grp 
       : grp.Skip(1)).SelectMany(i => i);