always enable primitive mixins

Author: gares

HB/factory.elpi

@@ -232,7 +232,7 @@ declare-mixin-or-factory MixinSrcClauses SectionCanonicalInstance
   abstract-over-section TheParams TheType MixinSrcClauses SectionCanonicalInstance coq.abstract-indt-decl RDecl RDeclClosed _,
 
 
-  if (get-option "primitive" tt)
+  if (get-option "primitive" tt ; not(Fields = end-record))
     (@primitive! => log.coq.env.add-indt RDeclClosed R)
     (log.coq.env.add-indt RDeclClosed R),