src/sage/symbolic/ginac: undo libgiac integration

If this is helping us in some way, I can't figure out how.

Author: orlitzky

src/sage/symbolic/ginac/basic.h

@@ -43,19 +43,6 @@ struct _object;
 typedef _object PyObject;
 #endif
 
-#ifdef PYNAC_HAVE_LIBGIAC
-namespace giac
-{
-        class gen;
-        template <class T> class tensor;
-        typedef class tensor<gen> polynome;
-}
-namespace GiNaC
-{
-struct ex_is_less;
-}
-#endif
-
 namespace GiNaC {
 
 class ex;
@@ -315,9 +302,6 @@ class basic : public refcounted
 	const basic & clearflag(unsigned f) const {flags &= ~f; return *this;}
 
 	void ensure_if_modifiable() const;
-#ifdef PYNAC_HAVE_LIBGIAC
-        const giac::polynome to_polynome(ex_int_map& map, exvector& revmap);
-#endif
 
 	// member variables
 	tinfo_t tinfo_key;                  ///< type info

src/sage/symbolic/ginac/ex.h

@@ -230,9 +230,6 @@ class ex {
 	ex to_rational(lst & repl_lst) const;
 	ex to_polynomial(exmap & repl) const;
 	ex to_polynomial(lst & repl_lst) const;
-#ifdef PYNAC_HAVE_LIBGIAC
-        const giac::polynome to_polynome(ex_int_map& map, exvector& revmap) const;
-#endif
         const CanonicalForm to_canonical(ex_int_umap& map,
                         power_ocvector_map& pomap, exvector& revmap) const;
         void collect_powers(power_ocvector_map& pomap) const;