[libc++] Implement ranges::fill{, _n}

Reviewed By: var-const, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D123462

NOKEYCHECK=True
GitOrigin-RevId: 7af89a379cce98382418be5b5433be6163e037f4
diff --git a/include/module.modulemap b/include/module.modulemap
index 6a771ea..d3a4b45 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -304,6 +304,8 @@
       module ranges_copy_n            { private header "__algorithm/ranges_copy_n.h" }
       module ranges_count             { private header "__algorithm/ranges_count.h" }
       module ranges_count_if          { private header "__algorithm/ranges_count_if.h" }
+      module ranges_fill              { private header "__algorithm/ranges_fill.h" }
+      module ranges_fill_n            { private header "__algorithm/ranges_fill_n.h" }
       module ranges_find              { private header "__algorithm/ranges_find.h" }
       module ranges_find_if           { private header "__algorithm/ranges_find_if.h" }
       module ranges_find_if_not       { private header "__algorithm/ranges_find_if_not.h" }