/usr/lib/xemacs-21.4.22/x86_64-linux-gnu/include/sheap-adjust.h is in xemacs21-bin 21.4.22-4ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | /* Do not edit this file!
Automatically generated by XEmacs */
#define SHEAP_ADJUSTMENT 0
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