Fix coding style issues pointed by Bill.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75898 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ELFWriter.h b/lib/CodeGen/ELFWriter.h
index 3cc50fe..ee5a856 100644
--- a/lib/CodeGen/ELFWriter.h
+++ b/lib/CodeGen/ELFWriter.h
@@ -34,6 +34,9 @@
   class TargetELFWriterInfo;
   class raw_ostream;
 
+  typedef std::vector<ELFSym*>::iterator ELFSymIter;
+  typedef std::vector<ELFSection*>::iterator ELFSectionIter;
+
   /// ELFWriter - This class implements the common target-independent code for
   /// writing ELF files.  Targets should derive a class from this to
   /// parameterize the output format.