Rustdoc inlined Deref impls should not include static methods.

[Stebalien]

As of #24396, rustdoc inlines Deref impls (:smiley:). However, static methods are also included. Static methods probably shouldn't be included as they can't be called through Deref. They also appear to mess with search results.

[aochagavia]

What about methods that take &mut self? Should we hide those too?

[alexcrichton]

@aochagavia nah I think including those is fine because they are applicable to a DerefMut implementation. In theory the "most correct" thing to do would be to detect whether DerefMut is implemented or not but it's also fine to not do that for now.