Dull series, sorry, but this is another change taken from wide-int. After checking host_integerp (now tree_fits_[su]hwi_p), the preferred way of getting the HWI seemed to be tree_low_cst (now tree_to_[su]hwi). This series mops up some cases where TREE_INT_CST_LOW was used directly.
Tested on x86_64-linux-gnu. Thanks, Richard
