INSTALL: recommend review/update of section on building a sharedperl library

Perl document "INSTALL" has a subsection called "Building a shared Perl 
library" 
(https://github.com/Perl/perl5/blob/1ef9039bccbfe64f47f201b6cfb7d6d23e0b08a7/INSTALL#L540), 
the bulk of which first appeared in the core distribution back in 1996:

#####
commit c3edaffb7eb74da112291acdf5874d2666d2ef54
Author:     unknown <perl5-porters@africa.nicoh.com>
AuthorDate: Thu Aug 22 03:11:00 1996 +0000
Commit:     Andy Dougherty <doughera@lafayette.edu>
CommitDate: Thu Aug 22 03:11:00 1996 +0000

     perl 5.003_03: INSTALL
#####

Apart from discussing the sequence of shell commands needed to build a 
shared Perl library, this subsection, then and now, (a) provides a 
discussion of the advantages and disadvantages of such a shared Perl 
library, and (b) gives an estimate of how much slower perl runs with a 
shared library.  Problem: the data cited in the speed estimate is still 
that from Solaris 2.5_x86 back in 1996.

This part of the documentation has not *substantially* changed in 26 
years.  It would benefit from review by one or two **people who have 
experience** with building shared Perl libraries (`-Duseshrplib`) and 
**running them in production environments**, both as to the pros and 
cons of such libraries and to their performance on contemporary OSes.

Thank you very much.
Jim Keenan

• INSTALL: recommend review/update of section on building a sharedperl library by James E Keenan
• Re: INSTALL: recommend review/update of section on building a sharedperl library by Felipe Gasper