FIX: Scaling of gcd of polynomials to be standard

[hulpke]

This fixes #3212

[fingolfin]

Unfortunately the same change must also be applied to hpcgap/lib/polyrat.gi. Could you please do that? Alternatively, I can amend your PR accordingly for you tomorrow.

[codecov]

Codecov Report

Merging #3227 into master will decrease coverage by 0.03%.
The diff coverage is 38.46%.

@@            Coverage Diff             @@
##           master    #3227      +/-   ##
==========================================
- Coverage    84.8%   84.77%   -0.04%     
==========================================
  Files         688      689       +1     
  Lines      331047   336349    +5302     
==========================================
+ Hits       280754   285133    +4379     
- Misses      50293    51216     +923

Impacted Files	Coverage Δ
lib/polyrat.gi	78.14% <33.33%> (-0.16%)	⬇️
hpcgap/lib/polyrat.gi	70.83% <42.85%> (-0.14%)	⬇️
src/vector.c	92.73% <0%> (-5.01%)	⬇️
src/hookintrprtr.c	67.34% <0%> (-4.88%)	⬇️
src/iostream.c	62.35% <0%> (-4.31%)	⬇️
src/lists.c	76.55% <0%> (-4.06%)	⬇️
src/vecffe.c	71.02% <0%> (-3.42%)	⬇️
src/c_type1.c	86.47% <0%> (-2.98%)	⬇️
src/vecgf2.c	73.3% <0%> (-2.56%)	⬇️
src/system.c	73.54% <0%> (-2.33%)	⬇️
... and 82 more

[fingolfin]

Thanks!

[coveralls]

Coverage increased (+0.003%) to 84.646% when pulling 4210bab on hulpke:fixes into f27cff4 on gap-system:master.

[fingolfin]

Backported to stable-4.10 in commit 9a6034d