avoid constructing list of all base-field elements in QuaternionAlgebra_ab.modp_splitting_data()

[yyyyx4]

This patch is from Rémy Oudompheng:

diff --git a/src/sage/algebras/quatalg/quaternion_algebra.py b/src/sage/algebras/quatalg/quaternion_algebra.py
index 3bde7b2153..3e12785e14 100644
--- a/src/sage/algebras/quatalg/quaternion_algebra.py
+++ b/src/sage/algebras/quatalg/quaternion_algebra.py
@@ -1232,7 +1232,7 @@ class QuaternionAlgebra_ab(QuaternionAlgebra_abstract):
             raise NotImplementedError("algorithm for computing local splittings not implemented in general (currently require the first invariant to be coprime to p)")
         i2inv = ~i2
         a = None
-        for b in list(F):
+        for b in F:
             if not b:
                 continue
             c = j2 + i2inv * b*b

Obviously, constructing a list of all elements is a very bad idea for non-tiny base fields.

CC: @slel @tscrim

Component: algebra

Author: Rémy Oudompheng

Branch/Commit: 91d3645

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/34355

[yyyyx4]

Commit: 91d3645

[yyyyx4]

Branch: public/34355

[tscrim]

comment:3

Indeed, indeed. LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[vbraun]

Changed branch from public/34355 to 91d3645