Log Message:
erlang: Update to 21.2.6

Changes:

 ---------------------------------------------------------------------
 --- erts-10.2.4 -----------------------------------------------------
 ---------------------------------------------------------------------

 --- Fixed Bugs and Malfunctions ---

  OTP-14728    Application(s): erts
               Related Id(s): ERIERL-303

               When using the {linger,{true,T}} option;
               gen_tcp:listen/2 used the full linger time before
               returning for example eaddrinuse. This bug has now been
               corrected.

 ---------------------------------------------------------------------
 --- stdlib-3.7.1 ----------------------------------------------------
 ---------------------------------------------------------------------

 --- Fixed Bugs and Malfunctions ---

  OTP-15573    Application(s): stdlib
               Related Id(s): ERIERL-306

               Optimize pretty printing of terms. The slower behaviour
               was introduced in Erlang/OTP 20.