Fix gh-3052, don't build ufunc when not used(We limit to 31 inputs when there is no C compiler)

theano/tensor/elemwise.py

@@ -505,7 +505,7 @@ class Elemwise(OpenMPOp):
         self.nfunc_spec = nfunc_spec
         if nfunc_spec:
             self.nfunc = getattr(numpy, nfunc_spec[0])
-        elif scalar_op.nin > 0:
+        elif scalar_op.nin > 0 and scalar_op.nin < 32:
             self.ufunc = numpy.frompyfunc(scalar_op.impl, scalar_op.nin,
                                           scalar_op.nout)
 
@@ -527,7 +527,7 @@ class Elemwise(OpenMPOp):
         self.nfunc = None
         if getattr(self, 'nfunc_spec', None):
             self.nfunc = getattr(numpy, self.nfunc_spec[0])
-        elif self.scalar_op.nin > 0:
+        elif self.scalar_op.nin > 0 and self.scalar_op.nin < 32:
             self.ufunc = numpy.frompyfunc(self.scalar_op.impl,
                                           self.scalar_op.nin,
                                           self.scalar_op.nout)