[libc++] Implement P1072R10 (std::basic_string::resize_and_overwrite)

Reviewed By: Quuxplusone, #libc, Mordante

Spies: mzeren-vmw, ckennelly, arichardson, ldionne, Mordante, libcxx-commits, Quuxplusone

Differential Revision: https://reviews.llvm.org/D113013

NOKEYCHECK=True
GitOrigin-RevId: bec50db2edf63c37ab48b1b9ca1ebb6a9fa47a59
diff --git a/docs/FeatureTestMacroTable.rst b/docs/FeatureTestMacroTable.rst
index 40e7558..3cfcaa6 100644
--- a/docs/FeatureTestMacroTable.rst
+++ b/docs/FeatureTestMacroTable.rst
@@ -328,6 +328,8 @@
     ------------------------------------------------- -----------------
     ``__cpp_lib_string_contains``                     ``202011L``
     ------------------------------------------------- -----------------
+    ``__cpp_lib_string_resize_and_overwrite``         ``202110L``
+    ------------------------------------------------- -----------------
     ``__cpp_lib_to_underlying``                       ``202102L``
     ================================================= =================