Wrap the return value of the type_id intrinsic in an opaque box

[emberian]

Closes #10594

[emberian]

I'm having a bit of difficulty with this one. When building stdtest, it gives:

│compile_and_link: x86_64-unknown-linux-gnu/stage1/test/stdtest-x86_64-unknown-linux-gnu
│/home/cmr/hacking/rust/src/libstd/any.rs:221:19: 221:28 error: failed to find an implementat
│ion of trait to_bytes::IterBytes for std::unstable::intrinsics::TypeId
│/home/cmr/hacking/rust/src/libstd/any.rs:221         assert_eq!(a.hash(), b.hash());
│                                                                ^~~~~~~~~
│<std-macros>:54:4: 67:5 note: in expansion of assert_eq!

Yet it's right there. What am I doing wrong?

[alexcrichton]

Why use realstd here?

[alexcrichton]

This may be having trouble because it's seeing an implementation of realstd::to_bytes::IterBytes, but it's not seeing an implementation of std::to_bytes::IterBytes. Just a guess though?

[emberian]

@alexcrichton does the same with most recent commit (using std instead of realstd). I really don't understand how libstd testing is set up at all...

[alexcrichton]

I think that this is the point where the boundary of testing libstd and running libstd gets so blurred that it's fine to move the relevant tests into a src/test/run-pass file.