How does JitIntrinsicAttribute affect code generation?

Question

I was browsing .NET source code and saw this attribute. It says,

An attribute that can be attached to JIT Intrinsic methods/properties

Answer 1

2018 update: apparently, [JitIntrinsic] was not used for its intended purpose and was replaced with System.Runtime.CompilerServices.IntrinsicAttribute.

The attribute was mentioned in the discussion about moving Vector classes to the CoreLib:

@jkotas: We should not need the JitIntrinsicAttribute. As far as I know, this attribute was future proofing, never used for anything real. We should delete it, and use the IntrinsicAttribute from CoreLib instead.

And later replaced with Intrinsic: Replace JitIntrinsicAttribute with IntrinsicAttribute.

See, What does the [Intrinsic] attribute in C# do? for the similar discussion about [Intrinsic] atrribute, which is actually used to implement low-level optimizations.