Parent._is_numerical, _is_real_numerical - remove hard dependency on real_mpfr, complex_mpfr

[mkoeppe]

This is for sagemath-polyhedra (#32432), which does not include the floating point fields

CC: @videlec @mezzarobba @tscrim @mjungmath

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: bf0ed1d

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/32625

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1,2 +1,2 @@
-This is for *'sagemath-polyhedra* (#32432), which does not include the floating point fields
+This is for **sagemath-polyhedra** (#32432), which does not include the floating point fields
 

[mkoeppe]

Branch: u/mkoeppe/parent__is_numerical___is_real_numerical___remove_hard_dependency_on_real_mpfr__complex_mpfr

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Commit: bf0ed1d

[mkoeppe]

New commits:

bf0ed1d

_is_[real_]numerical: Fall back to using CDF/RDF if ComplexField, RealField cannot be imported

[tscrim]

comment:5

LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[mkoeppe]

comment:6

Thanks!

[vbraun]

Changed branch from u/mkoeppe/parent__is_numerical___is_real_numerical___remove_hard_dependency_on_real_mpfr__complex_mpfr to bf0ed1d