Fix minor typo


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3630 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/WritingAnLLVMPass.html b/docs/WritingAnLLVMPass.html
index d1cf63c..353fe6e 100644
--- a/docs/WritingAnLLVMPass.html
+++ b/docs/WritingAnLLVMPass.html
@@ -194,7 +194,7 @@
 
 This declares a "<tt>Hello</tt>" class that is a subclass of <tt><a
 href="http://llvm.cs.uiuc.edu/doxygen/structFunctionPass.html">FunctionPass</a></tt>.
-The different builting pass subclasses are described in detail <a
+The different builtin pass subclasses are described in detail <a
 href="#passtype">later</a>, but for now, know that <a href="#FunctionPass"><tt>FunctionPass</tt></a>'s
 operate a function at a time.<p>