Fix some thinkos in MSVC regex hack

The changed code is not used, but I tried to use a similar approach for
boost::regex, and found some problems:
- regex_replace and regex_search are implemented in the replacement, so they
  must not be used directly
- an smatch object must be given by reference (as in the called methods),
  otherwise an exception would be thrown at runtime
- the commented out regex_replace version is actually needed

This code is supposed to be deleted, but nevertheless I wanted to record here
how it had to be modified if it was actually needed.

src/support/regex.h

@@ -17,7 +17,7 @@
 #  ifdef _MSC_VER
 namespace lyx {
   // inheriting 'private' to see which functions are used and if there are
-  // other ECMAScrip defaults
+  // other ECMAScript defaults
   // FIXME: Is this really needed?
   //        If yes, then the MSVC regex implementation is not standard-conforming.
   class regex : private std::regex
@@ -35,20 +35,20 @@ namespace lyx {
   };
   template<class T>
   bool regex_match(T t, const regex& r) { return std::regex_match(t, r.toStd()); }
+  template<class T>
+  bool regex_match(T t, std::smatch& m, const regex& r) { return std::regex_match(t, m, r.toStd()); }
   template<class T, class V>
-  bool regex_match(T t, V v, const regex& r) { return std::regex_match(t, v, r.toStd()); }
+  bool regex_match(T t, V v, std::smatch& m, const regex& r) { return std::regex_match(t, v, m, r.toStd()); }
-  template<class T, class V, class U, class H>
-  bool regex_match(T t, V v, H h, const regex& r, U u) { return std::regex_match(t, v, h, r.toStd(), u); }
   template<class T, class V>
   std::string regex_replace(T t, const regex& r, V v) { return std::regex_replace(t, r.toStd(), v); }
-  //template<class T, class V, class U, class H>
+  template<class T, class V, class U, class H>
-  //std::string regex_replace(T t, V v, U u, const regex& r, H h) { return std::regex_replace(t, v, u, r.toStd(), h); }
+  T regex_replace(T t, V v, U u, const regex& r, H h) { return std::regex_replace(t, v, u, r.toStd(), h); }
   template<class T>
   bool regex_search(T t, const regex& r) { return std::regex_search(t, r.toStd()); }
+  template<class T>
+  bool regex_search(T t, std::smatch& m, const regex& r) { return std::regex_search(t, m, r.toStd()); }
   template<class T, class V>
-  bool regex_search(T t, V v, const regex& r) { return std::regex_search(t, v, r.toStd()); }
+  bool regex_search(T t, V v, std::smatch& m, const regex& r) { return std::regex_search(t, v, m, r.toStd()); }
-  template<class T, class V, class U>
-  bool regex_search(T t, V v, U u, const regex& r) { return std::regex_search(t, v, u, r.toStd()); }
 
   struct sregex_iterator : std::sregex_iterator
   {
@@ -64,6 +64,8 @@ namespace lyx {
 namespace lyx {
 using LR_NS::regex;
 using LR_NS::regex_match;
+using LR_NS::regex_replace;
+using LR_NS::regex_search;
 using LR_NS::sregex_iterator;
 }
 #  endif
@@ -73,16 +75,16 @@ using LR_NS::sregex_iterator;
 namespace lyx {
 using LR_NS::regex;
 using LR_NS::regex_match;
+using LR_NS::regex_replace;
+using LR_NS::regex_search;
 using LR_NS::sregex_iterator;
 }
 #endif
 
 namespace lyx {
 using LR_NS::smatch;
-using LR_NS::regex_replace;
 using LR_NS::basic_regex;
 using LR_NS::regex_error;
-using LR_NS::regex_search;
 using LR_NS::match_results;
 
 namespace regex_constants