Apparently it's possible to do an 'invoke asm'.
Update the language reference to reflect that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160408 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 9793659..c32c98c 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -2867,8 +2867,9 @@
 </pre>
 
 <p>Inline assembler expressions may <b>only</b> be used as the callee operand of
-   a <a href="#i_call"><tt>call</tt> instruction</a>.  Thus, typically we
-   have:</p>
+   a <a href="#i_call"><tt>call</tt></a> or an
+   <a href="#i_invoke"><tt>invoke</tt></a> instruction.
+   Thus, typically we have:</p>
 
 <pre class="doc_code">
 %X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)