internal/reflectlite: use unsafe.String in name.name and name.tag

internal/reflectlite: use unsafe.String in name.name and name.tag

Same as CL 448675 did in package reflect.

Change-Id: I26277d8dcf2d2e204724d6fa5cc6e1ad391633f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/448936
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>