fix isPromotable ring family

Author: pzinn

M2/Macaulay2/m2/typicalvalues.m2

@@ -319,6 +319,12 @@ taylor (log1p, (x,n) -> (
     s
     ))
 
+promote(RR',RR') :=
+promote(RR',CC') :=
+promote(CC',CC') :=
+promote(RR',CC') :=
+promote(RR',RRi') :=
+promote(RRi',RRi') := dummy
 
 -- Local Variables:
 -- compile-command: "make -C $M2BUILDDIR/Macaulay2/m2 "