Fix ICE when casting on constant expressions. Closes #9867
Remove rusti target in Makefile.in (Fixes compilation failure due to rusti's removal)
auto merge of #9909 : LeoTestard/rust/master, r=thestinger

This pull request fixes the bug I opened ( #9867 )
It also fixes a small issue that was causing Rustc build to fail on my setup, by removing a rusti target in the Makefile.