Provide missing '{' in parsing extended quoted characters.  This fixes http://llvm.org/bugs/show_bug.cgi?id=16135

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@185211 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/regex b/include/regex
index 75c61db..52c9178 100644
--- a/include/regex
+++ b/include/regex
@@ -3420,6 +3420,7 @@
                 case '+':
                 case '?':
                 case '{':
+                case '}':
                     __push_char(*__temp);
                     __first = ++__temp;
                     break;