Fix "TODO forward zero-set of arraycopy used memset rather than runtime type "

[vchuravy]

https://github.com/EnzymeAD/Enzyme.jl/blob/8dde0343d7b4fdc92ecf4fe4fafd7e7df7cf1427/src/rules/llvmrules.jl#L335-L336

https://github.com/EnzymeAD/Enzyme.jl/blob/8dde0343d7b4fdc92ecf4fe4fafd7e7df7cf1427/src/rules/llvmrules.jl#L358-L359

I just got log-spammed with this:

┌ Warning: TODO forward zero-set of arraycopy used memset rather than runtime type 
│ Caused by:
│ Stacktrace:
│  [1] copy
│    @ ./array.jl:411
│  [2] unaliascopy
│    @ ./abstractarray.jl:1497
│  [3] unalias
│    @ ./abstractarray.jl:1481
│  [4] copyto!
│    @ ./abstractarray.jl:1067
│  [5] set!
│    @ ~/src/Chmy/src/Fields/field.jl:98
│  [6] set!
│    @ ~/src/Chmy/src/Fields/field.jl:0
└ @ Enzyme.Compiler ~/.julia/packages/GPUCompiler/y4cj1/src/utils.jl:59

[vchuravy]

Log-spam was triggered by https://github.com/EnzymeAD/Enzyme.jl/issues/1779#issuecomment-2328248954