doc: remove duplicate -asmflags mention

Fixes #12053

Change-Id: Icd883b4f1ac944a8ec718c79770a8e3fc6542e3a
Reviewed-on: https://go-review.googlesource.com/13259
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/doc/go1.5.html b/doc/go1.5.html
index 70ce94e..5f6e5f7 100644
--- a/doc/go1.5.html
+++ b/doc/go1.5.html
@@ -523,14 +523,6 @@
 </li>
 
 <li>
-An <code>-asmflags</code> build option has been added to provide
-flags to the assembler.
-However,
-the <code>-ccflags</code> build option has been dropped;
-it was specific to the old, now deleted C compiler .
-</li>
-
-<li>
 A new <code>-pkgdir</code> build option
 sets the location of installed package archives,
 to help isolate custom builds.