[wwwdoc][Patch] Mention Loongson 3a1000 3a2000 3a3000 2k1000 support in gcc9

[Gerald Pfeifer]

Hi Paul,

On Mon, 31 Dec 2018, Paul Hua wrote:
> The attached patch mention Loongson 3a1000 3a2000 3a3000 2k1000 support 
> in gcc9.

thanks for putting this together.  Only a couple of editorial changes:

Index: changes.html
===================================================================
+  <li>
+    The Loongson <code>loongson-mmi</code> and <code>loongson-ext</code>
+    extension has now been splited from <code>loongson3a</code>:

"...extensions have been split..."

+    <ul>
+       <li><code>loongson-mmi</code> which contains 
+       the Loongson MultiMedia extension Instructions operations.</li>
+       <li><code>loongson-ext</code> which contains 
+       the Loongson EXTension instructions.</li>

Here I'd omit omit the two instances of "which"

+    The Loongson EXTension R2 instructions is now supported.

"is" -> "are"

+    Use -mxxx or -mno-xxx will enable or disable those extersions.

Since it's only two options, how about listing both of them?

"extersion" -> "extension"

+    for example: Using <code>-mloongson-mmi</code>/<code>-mno-loongson-mmi</code> 
+    will enable/disable Loongson MultiMedia Instructions extensions.

"...the Loongson MultiMedia Instructions extension."

+	which default enable <code>loongson-mmi</code>, <code>loongson-ext</code>.</li>

"which enables ... by default"  (also in the following two items)


Please look into those comments and then simply post the updated patch
as you're committing it.

Gerald