Driver: Fix off by one in computation of first searchable option.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67552 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/OptTable.cpp b/lib/Driver/OptTable.cpp
index 283ebf9..e773c66 100644
--- a/lib/Driver/OptTable.cpp
+++ b/lib/Driver/OptTable.cpp
@@ -91,7 +91,7 @@
   FirstSearchableOption = 0;
   for (unsigned i = OPT_UNKNOWN + 1; i < LastOption; ++i) {
     if (getInfo(i).Kind != Option::GroupClass) {
-      FirstSearchableOption = i + 1;
+      FirstSearchableOption = i;
       break;
     }
   }