Bitcode: Correctly compare a Use against itself

Fix the sort of expected order in the reader to correctly return `false`
when comparing a `Use` against itself.

This was caught by test/Bitcode/binaryIntInstructions.3.2.ll, so I'm
adding a `RUN` line using `llvm-uselistorder` for every test in
`test/Bitcode` that passes.

A few tests still fail, so I'll investigate those next.

This is part of PR5680.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214157 91177308-0d34-0410-b5e6-96231b3b80d8

test/Bitcode/select.ll

@@ -1,4 +1,5 @@
 ; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+; RUN: llvm-uselistorder < %s -preserve-bc-use-list-order -num-shuffles=5
 
 define <2 x i32> @main() {
   ret <2 x i32> select (<2 x i1> <i1 false, i1 undef>, <2 x i32> zeroinitializer, <2 x i32> <i32 0, i32 undef>)