libcxx: Update to LLVM 19.

* Moved the tz.cpp patch to experimental/tzdb.cpp.
* Extended the __config_site patch to a few more files.

lib/libcxx/include/regex

@@ -791,8 +791,7 @@ typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;
 
 #include <__algorithm/find.h>
 #include <__algorithm/search.h>
-#include <__assert> // all public C++ headers provide the assertion handler
-#include <__availability>
+#include <__assert>
 #include <__config>
 #include <__iterator/back_insert_iterator.h>
 #include <__iterator/default_sentinel.h>
@@ -1346,13 +1345,12 @@ struct __state {
 
 template <class _CharT>
 class __node {
-  __node(const __node&);
-  __node& operator=(const __node&);
-
 public:
   typedef std::__state<_CharT> __state;
 
   _LIBCPP_HIDE_FROM_ABI __node() {}
+  __node(const __node&)            = delete;
+  __node& operator=(const __node&) = delete;
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL
   virtual ~__node() {}
 
@@ -1953,14 +1951,14 @@ class __match_char : public __owns_one_state<_CharT> {
 
   _CharT __c_;
 
-  __match_char(const __match_char&);
-  __match_char& operator=(const __match_char&);
-
 public:
   typedef std::__state<_CharT> __state;
 
   _LIBCPP_HIDE_FROM_ABI __match_char(_CharT __c, __node<_CharT>* __s) : base(__s), __c_(__c) {}
 
+  __match_char(const __match_char&)            = delete;
+  __match_char& operator=(const __match_char&) = delete;
+
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __exec(__state&) const;
 };
 
@@ -1985,15 +1983,15 @@ class __match_char_icase : public __owns_one_state<_CharT> {
   _Traits __traits_;
   _CharT __c_;
 
-  __match_char_icase(const __match_char_icase&);
-  __match_char_icase& operator=(const __match_char_icase&);
-
 public:
   typedef std::__state<_CharT> __state;
 
   _LIBCPP_HIDE_FROM_ABI __match_char_icase(const _Traits& __traits, _CharT __c, __node<_CharT>* __s)
       : base(__s), __traits_(__traits), __c_(__traits.translate_nocase(__c)) {}
 
+  __match_char_icase(const __match_char_icase&)            = delete;
+  __match_char_icase& operator=(const __match_char_icase&) = delete;
+
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __exec(__state&) const;
 };
 
@@ -2018,15 +2016,15 @@ class __match_char_collate : public __owns_one_state<_CharT> {
   _Traits __traits_;
   _CharT __c_;
 
-  __match_char_collate(const __match_char_collate&);
-  __match_char_collate& operator=(const __match_char_collate&);
-
 public:
   typedef std::__state<_CharT> __state;
 
   _LIBCPP_HIDE_FROM_ABI __match_char_collate(const _Traits& __traits, _CharT __c, __node<_CharT>* __s)
       : base(__s), __traits_(__traits), __c_(__traits.translate(__c)) {}
 
+  __match_char_collate(const __match_char_collate&)            = delete;
+  __match_char_collate& operator=(const __match_char_collate&) = delete;
+
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __exec(__state&) const;
 };
 
@@ -2062,9 +2060,6 @@ class __bracket_expression : public __owns_one_state<_CharT> {
   bool __collate_;
   bool __might_have_digraph_;
 
-  __bracket_expression(const __bracket_expression&);
-  __bracket_expression& operator=(const __bracket_expression&);
-
 public:
   typedef std::__state<_CharT> __state;
 
@@ -2079,6 +2074,9 @@ public:
         __collate_(__collate),
         __might_have_digraph_(__traits_.getloc().name() != "C") {}
 
+  __bracket_expression(const __bracket_expression&)            = delete;
+  __bracket_expression& operator=(const __bracket_expression&) = delete;
+
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __exec(__state&) const;
 
   _LIBCPP_HIDE_FROM_ABI bool __negated() const { return __negate_; }
@@ -2700,9 +2698,6 @@ class __lookahead : public __owns_one_state<_CharT> {
   unsigned __mexp_;
   bool __invert_;
 
-  __lookahead(const __lookahead&);
-  __lookahead& operator=(const __lookahead&);
-
 public:
   typedef std::__state<_CharT> __state;
 
@@ -2710,6 +2705,9 @@ public:
   __lookahead(const basic_regex<_CharT, _Traits>& __exp, bool __invert, __node<_CharT>* __s, unsigned __mexp)
       : base(__s), __exp_(__exp), __mexp_(__mexp), __invert_(__invert) {}
 
+  __lookahead(const __lookahead&)            = delete;
+  __lookahead& operator=(const __lookahead&) = delete;
+
   _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __exec(__state&) const;
 };
 
@@ -4215,11 +4213,7 @@ public:
   _LIBCPP_HIDE_FROM_ABI int compare(const string_type& __s) const { return str().compare(__s); }
   _LIBCPP_HIDE_FROM_ABI int compare(const value_type* __s) const { return str().compare(__s); }
 
-  _LIBCPP_HIDE_FROM_ABI void swap(sub_match& __s)
-#ifndef _LIBCPP_CXX03_LANG
-      _NOEXCEPT(__is_nothrow_swappable<_BidirectionalIterator>::value)
-#endif // _LIBCPP_CXX03_LANG
-  {
+  _LIBCPP_HIDE_FROM_ABI void swap(sub_match& __s) _NOEXCEPT_(__is_nothrow_swappable_v<_BidirectionalIterator>) {
     this->pair<_BidirectionalIterator, _BidirectionalIterator>::swap(__s);
     std::swap(matched, __s.matched);
   }
@@ -4583,7 +4577,7 @@ public:
   // size:
   _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __matches_.size(); }
   _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __matches_.max_size(); }
-  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return size() == 0; }
+  _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return size() == 0; }
 
   // element access:
   _LIBCPP_HIDE_FROM_ABI difference_type length(size_type __sub = 0) const {
@@ -4701,6 +4695,9 @@ private:
 
   template <class, class>
   friend class __lookahead;
+
+  template <class, class, class>
+  friend class regex_iterator;
 };
 
 template <class _BidirectionalIterator, class _Allocator>
@@ -5411,7 +5408,9 @@ template <class _BidirectionalIterator, class _CharT, class _Traits>
 regex_iterator<_BidirectionalIterator, _CharT, _Traits>&
 regex_iterator<_BidirectionalIterator, _CharT, _Traits>::operator++() {
   __flags_ |= regex_constants::__no_update_pos;
-  _BidirectionalIterator __start = __match_[0].second;
+  _BidirectionalIterator __start        = __match_[0].second;
+  _BidirectionalIterator __prefix_start = __start;
+
   if (__match_[0].first == __match_[0].second) {
     if (__start == __end_) {
       __match_ = value_type();
@@ -5425,9 +5424,21 @@ regex_iterator<_BidirectionalIterator, _CharT, _Traits>::operator++() {
     else
       ++__start;
   }
+
   __flags_ |= regex_constants::match_prev_avail;
-  if (!std::regex_search(__start, __end_, __match_, *__pregex_, __flags_))
+  if (!std::regex_search(__start, __end_, __match_, *__pregex_, __flags_)) {
     __match_ = value_type();
+
+  } else {
+    // The Standard mandates that if `regex_search` returns true ([re.regiter.incr]), "`match.prefix().first` shall be
+    // equal to the previous value of `match[0].second`... It is unspecified how the implementation makes these
+    // adjustments." The adjustment is necessary if we incremented `__start` above (the branch that deals with
+    // zero-length matches).
+    auto& __prefix   = __match_.__prefix_;
+    __prefix.first   = __prefix_start;
+    __prefix.matched = __prefix.first != __prefix.second;
+  }
+
   return *this;
 }