Commit 9f71f697 authored by Simon Peyton Jones's avatar Simon Peyton Jones Committed by Marge Bot

Add two bangs to improve perf of flattening

This tiny patch improves the compile time of flatten-heavy
programs by 1-2%, by adding two bangs.

Addresses (somewhat) #18502

This reduces allocation by
   T9872b   -1.1%
   T9872d   -3.3%

   T5321Fun -0.2%
   T5631    -0.2%
   T5837    +0.1%
   T6048    +0.1%

Metric Decrease:
parent ebe2cf45
Pipeline #22815 failed with stages
in 400 minutes and 47 seconds