x86: use symname in IntelSyntax and GNUSyntax

Change-Id: I8b75df1c9dedb402a227182588b2dea4f82d348a
Reviewed-on: https://go-review.googlesource.com/45098
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
6 files changed