document pointer type constraints, PR3513


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64088 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.html b/docs/LangRef.html
index e58d159..dc6d7f2 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -1561,6 +1561,10 @@
 an optional address space attribute defining the target-specific numbered 
 address space where the pointed-to object resides. The default address space is 
 zero.</p>
+
+<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does 
+it permit pointers to labels (<tt>label*</tt>).  Use <tt>i8*</aa> intead.</p>
+
 <h5>Syntax:</h5>
 <pre>  &lt;type&gt; *<br></pre>
 <h5>Examples:</h5>