libcxx: update to LLVM 18

release/18.x branch, commit 78b99c73ee4b96fe9ce0e294d4632326afb2db42

This adds the flag `-D_LIBCPP_HARDENING_MODE` which is determined based
on the Zig optimization mode.

This commit also fixes libunwind, libcxx, and libcxxabi to properly
report sub compilation errors.

1 files changed, 26 insertions, 22 deletions

diff --git a/lib/libcxx/include/__algorithm/shift_left.h b/lib/libcxx/include/__algorithm/shift_left.h
index 023b56dcfc..06cd7c5f87 100644
--- a/lib/libcxx/include/__algorithm/shift_left.h
+++ b/lib/libcxx/include/__algorithm/shift_left.h
@@ -17,39 +17,43 @@
 #  pragma GCC system_header
 #endif
 
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if _LIBCPP_STD_VER >= 20
 
 template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY constexpr
-_ForwardIterator
-shift_left(_ForwardIterator __first, _ForwardIterator __last,
-           typename iterator_traits<_ForwardIterator>::difference_type __n)
-{
-    if (__n == 0) {
-        return __last;
+inline _LIBCPP_HIDE_FROM_ABI constexpr _ForwardIterator
+shift_left(_ForwardIterator __first,
+           _ForwardIterator __last,
+           typename iterator_traits<_ForwardIterator>::difference_type __n) {
+  if (__n == 0) {
+    return __last;
+  }
+
+  _ForwardIterator __m = __first;
+  if constexpr (__has_random_access_iterator_category<_ForwardIterator>::value) {
+    if (__n >= __last - __first) {
+      return __first;
     }
-
-    _ForwardIterator __m = __first;
-    if constexpr (__has_random_access_iterator_category<_ForwardIterator>::value) {
-        if (__n >= __last - __first) {
-            return __first;
-        }
-        __m += __n;
-    } else {
-        for (; __n > 0; --__n) {
-            if (__m == __last) {
-                return __first;
-            }
-            ++__m;
-        }
+    __m += __n;
+  } else {
+    for (; __n > 0; --__n) {
+      if (__m == __last) {
+        return __first;
+      }
+      ++__m;
     }
-    return _VSTD::move(__m, __last, __first);
+  }
+  return std::move(__m, __last, __first);
 }
 
 #endif // _LIBCPP_STD_VER >= 20
 
 _LIBCPP_END_NAMESPACE_STD
 
+_LIBCPP_POP_MACROS
+
 #endif // _LIBCPP___ALGORITHM_SHIFT_LEFT_H