[libc++][PSTL] Implement std::equal (#72448)

Differential Revision: https://reviews.llvm.org/D157131

Co-authored-by: Louis Dionne <[email protected]>
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 578de74..627e7d2 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -1826,6 +1826,7 @@
 #include <__algorithm/pstl_any_all_none_of.h>
 #include <__algorithm/pstl_copy.h>
 #include <__algorithm/pstl_count.h>
+#include <__algorithm/pstl_equal.h>
 #include <__algorithm/pstl_fill.h>
 #include <__algorithm/pstl_find.h>
 #include <__algorithm/pstl_for_each.h>