IR: Set -preserve-bc-uselistorder=false by default

But keep it on by default in `llvm-as`, `opt`, `bugpoint`, `llvm-link`,
`llvm-extract`, and `LTOCodeGenerator`.  Part of PR5680.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234921 91177308-0d34-0410-b5e6-96231b3b80d8

tools/opt/opt.cpp

@@ -30,6 +30,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LegacyPassNameParser.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/UseListOrder.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/InitializePasses.h"
@@ -344,6 +345,10 @@ int main(int argc, char **argv) {
   polly::initializePollyPasses(Registry);
 #endif
 
+  // Turn on -preserve-bc-uselistorder by default, but let the command-line
+  // override it.
+  setPreserveBitcodeUseListOrder(true);
+
   cl::ParseCommandLineOptions(argc, argv,
     "llvm .bc -> .bc modular optimizer and analysis printer\n");