minor long double related changes

llvm-svn: 42439
diff --git a/llvm/tools/llvm-upgrade/UpgradeLexer.l.cvs b/llvm/tools/llvm-upgrade/UpgradeLexer.l.cvs
index 5318736..9ab9eee 100644
--- a/llvm/tools/llvm-upgrade/UpgradeLexer.l.cvs
+++ b/llvm/tools/llvm-upgrade/UpgradeLexer.l.cvs
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 //
 //  This file implements the flex scanner for LLVM 1.9 assembly languages files.
+//  This doesn't handle long double constants, since LLVM 1.9 did not have them.
 //
 //===----------------------------------------------------------------------===*/