I used the header files below to make old HP-UX 11.11 (a.k.a. 11i v1) more compatible with modern software requiring newer POSIX standards and some GNU extensions. They can be used to bootstrap modern GCC starting with HP aCC and some ancient GCC versions.
The files in this gist are to be placed in /usr/local/include. The
files sys -- stat.h and sys -- sendfile.h should be placed in
/usr/local/include/sys as stat.h and sendfile.h, respectively.