Add support for new features available in gccgo 4.7, notably calling

Entersyscall and Exitsyscall around calls to wrapped C/C++ code.


git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12940 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Doc/Manual/Go.html

@@ -99,6 +99,19 @@ swig -go -help
   6g/8g/5g.</td>
 </tr>
 
+<tr>
+<td>-gccgo-46</td>
+<td>Generate code for gccgo 4.6.  The default is set by the configure
+  script.</td>  This generates code that does not use some facilities
+  that are only available in gccgo 4.7 and later.
+</tr>
+
+<tr>
+<td>-no-gccgo-46</td>
+<td>Turn off <code>-gccgo-46</code>, whether set by default or earlier
+  on the command line.
+</tr>
+
 <tr>
 <td>-package &lt;name&gt;</td>
 <td>Set the name of the Go package to &lt;name&gt;.  The default