Fix typos found by http://github.com/lyda/misspell-check

llvm-svn: 157885
diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index d9a535c..477b81d 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -1723,7 +1723,7 @@
   }
       
   case IITDescriptor::Argument:
-    // Two cases here - If this is the second occurrance of an argument, verify
+    // Two cases here - If this is the second occurrence of an argument, verify
     // that the later instance matches the previous instance. 
     if (D.getArgumentNumber() < ArgTys.size())
       return Ty != ArgTys[D.getArgumentNumber()];