doc/asm.html: remove mention of 6l -a
Also make it clear this is not a complete description of all features.
Fixes #7790.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/88300044
diff --git a/doc/asm.html b/doc/asm.html
index b855b9e..860bc57 100644
--- a/doc/asm.html
+++ b/doc/asm.html
@@ -8,7 +8,11 @@
<p>
This document is a quick outline of the unusual form of assembly language used by the <code>gc</code>
suite of Go compilers (<code>6g</code>, <code>8g</code>, etc.).
-It is based on the input to the Plan 9 assemblers, which is documented in detail
+The document is not comprehensive.
+</p>
+
+<p>
+The assembler is based on the input to the Plan 9 assemblers, which is documented in detail
<a href="http://plan9.bell-labs.com/sys/doc/asm.html">on the Plan 9 site</a>.
If you plan to write assembly language, you should read that document although much of it is Plan 9-specific.
This document provides a summary of the syntax and
@@ -70,6 +74,8 @@
for use by the garbage collector; they are introduced by the compiler.
</p>
+<!-- Commenting out because the feature is gone but it's popular and may come back.
+
<p>
To see what gets put in the binary after linking, add the <code>-a</code> flag to the linker:
</p>
@@ -98,6 +104,7 @@
...
</pre>
+-->
<h3 id="symbols">Symbols</h3>
