[Kaleidoscope] Fix symbol resolver to search in reverse order.

This should allow more recent definitions of functions in the Kaleidoscope REPL
to override old ones, as the tutorial text promises.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354598 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed