Fix a typo I happened to notice.
Rename include guards in the "usual" manner.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8695 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Support/InstIterator.h b/include/llvm/Support/InstIterator.h
index e9db75b..06fc9bd 100644
--- a/include/llvm/Support/InstIterator.h
+++ b/include/llvm/Support/InstIterator.h
@@ -9,13 +9,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_INST_ITERATOR_H
-#define LLVM_INST_ITERATOR_H
+#ifndef LLVM_SUPPORT_INSTITERATOR_H
+#define LLVM_SUPPORT_INSTITERATOR_H
 
 #include "llvm/BasicBlock.h"
 #include "llvm/Function.h"
 
-// This class is implements inst_begin() & inst_end() for
+// This class implements inst_begin() & inst_end() for
 // inst_iterator and const_inst_iterator's.
 //
 template <class _BB_t, class _BB_i_t, class _BI_t, class _II_t>