[BUG] Can't use SIMD data types as keys for Dicts

[schtschenok]

Bug description

Can't use SIMD data types (UInt8, Int16, etc.) as Dict keys despite that SIMD seems to fit KeyElement requirements.

Steps to reproduce

from collections import Dict

var map1 = Dict[Int, UInt8]()  # Works
var map2 = Dict[UInt8, UInt8]()  # Doesn't work

System information

Ubuntu 22.04.4 LTS running in WSL on Windows 11 24H2
mojo 24.4.0 (59977802)
modular 0.9.2 (b3079bd5)

[jjvraw]

SIMD's __eq__/__ne__ methods returns a bool SIMD vector, which differs to the conformance of EqualityComparable, of which KeyElement inherits

[JoeLoser]

Yep, this is working as intended right now, even though it's unfortunate. There's other tracking issues for making SIMD regular (so that its eq and ne would return a Bool and thus compose nicely).