runtime: remove go:nosplit comment from reflect.typelinks

A nosplit comment was added to reflect.typelinks accidentally in
https://golang.org/cl/98510044.  There is only one caller of
reflect.typelinks, reflect.typesByString, and that function is not
nosplit.  There is no reason for reflect.typelinks to be nosplit.

Change-Id: I0fd3cc66fafcd92643e38e53fa586d6b2f868a0a
Reviewed-on: https://go-review.googlesource.com/16932
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

src/runtime/runtime1.go

@@ -453,7 +453,6 @@ func gomcache() *mcache {
 }
 
 //go:linkname reflect_typelinks reflect.typelinks
-//go:nosplit
 func reflect_typelinks() [][]*_type {
 	ret := [][]*_type{firstmoduledata.typelinks}
 	for datap := firstmoduledata.next; datap != nil; datap = datap.next {