jdk14 build failed cause "The header is deprecated and will be removed."

[451541695]

Hello,  Thanks for providing java for developers.
  I am trying to build jdk-14 to use, but failed to build.
  The error is following:

   My environment:
      Linux: Ubuntu 20.04.1 LTS
      autoconfig:

&nbsp;I don't know what happened to <sys/sysctl.h&gt;, my Ubuntu version is too 
high?
Long for your replying.