XFAIL a couple of new <regex> tests for C++03

llvm-svn: 313064
diff --git a/libcxx/test/std/re/re.alg/re.alg.search/exponential.pass.cpp b/libcxx/test/std/re/re.alg/re.alg.search/exponential.pass.cpp
index c48cc94..eba76c8 100644
--- a/libcxx/test/std/re/re.alg/re.alg.search/exponential.pass.cpp
+++ b/libcxx/test/std/re/re.alg/re.alg.search/exponential.pass.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 // <regex>
+// XFAIL: c++03
 
 // template <class BidirectionalIterator, class Allocator, class charT, class traits>
 //     bool