runtime: inline and remove eqtype

Now that type equality is just a pointer equality, write it
inlined and remove the eqtype function.

Change-Id: Ie3f27be0a4cb6f7dc2b6470dd5ae63c6c8beed42
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/182978
Reviewed-by: Ian Lance Taylor <iant@golang.org>
3 files changed