Use List<T>.ToArray() in places

[benaadams]

Also List<T>.ToArray() rather than creating a new array and then .CopyTo

[jkotas]

Looks good to me otherwise. Thanks!

[benaadams]

Checking the effects on the generics

[benaadams]

Just gone for the easy wins

Total bytes of diff: -175 (-0.01% of base)
    diff is an improvement.

Total byte diff includes 0 bytes from reconciling methods
        Base had    0 unique methods,        0 unique bytes
        Diff had    0 unique methods,        0 unique bytes

Top file improvements by size (bytes):
        -175 : System.Private.CoreLib.dasm (-0.01% of base)

1 total files with size differences (1 improved, 0 regressed), 0 unchanged.

Top method improvements by size (bytes):
         -82 : System.Private.CoreLib.dasm - RuntimeType:InvokeMember(ref,int,ref,ref,ref,ref,ref,ref):ref:this
         -57 : System.Private.CoreLib.dasm - DateTimeFormat:GetAllDateTimes(struct,ref):ref
         -36 : System.Private.CoreLib.dasm - RuntimeType:CreateInstanceImpl(int,ref,ref,ref,ref):ref:this

3 total methods with size differences (3 improved, 0 regressed), 17217 unchanged.

This had a negative impact?

Depends on how you look at it

Top method regessions by size (bytes):
          46 : System.Private.CoreLib.dasm - StackTrace:GetFrames():ref:this
          26 : System.Private.CoreLib.dasm - MemoryStream:ToArray():ref:this

However that's from the validation and throws surfacing in the methods from creating the ReadOnlySpan; its likely to be a faster path after that.

[benaadams]

Could probably bring that back by using the ref Span constructor, but I was feeling uncontroversial ;)