Fix bugs reported by Will Drewry: certain invalid regexes can cause the library to access invalid memory, changed to ensure that the correct exception is thrown long before this happens.

[SVN r42674]

libs/regex

@@ -1 +1 @@
-Subproject commit 07eaac9e0e418f2ef7730825b5c69ea76eacba06
+Subproject commit 299086b99cb11b3eb246f9a53bed927e784b8d12