[perl #131915] [Regression] Proc using more memory since being a Proc::Async

[via RT]

# New Ticket Created by  Sylvain Colinet 
# Please include the string:  [perl #131915]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131915 >


Similar to https://rt.perl.org/m/ticket/show?id=131914 it was noticed that 
there is a huge increase of memory usage after running a simple echo command.
Result are in Kbytes.

<AlexDaniel> commit: 
92bd7e4f54a9^,92bd7e4f54a9,9658dd98c9dd8ec^^,9658dd98c9dd8ec sub mem { 
"/proc/$*PID/statm".IO.lines[0].split(/\s/)[5] * 4096 / 1024 }; say mem(); run 
'echo'; say mem()
<committable6test> AlexDaniel, ¦92bd7e4f54a9^: «56444␤␤59820» ¦92bd7e4: 
«56568␤␤215976» ¦9658dd98c9dd8ec^^: «59212␤␤216660» ¦9658dd9: «139024␤␤305320»