Assert that we have all use/users in the getters.

An error that is pretty easy to make is to use the lazy bitcode reader
and then do something like

if (V.use_empty())

The problem is that uses in unmaterialized functions are not accounted
for.

This patch adds asserts that all uses are known.

llvm-svn: 256105

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -3028,7 +3028,7 @@ std::error_code BitcodeReader::parseUseLists() {
         V = ValueList[ID];
       unsigned NumUses = 0;
       SmallDenseMap<const Use *, unsigned, 16> Order;
-      for (const Use &U : V->uses()) {
+      for (const Use &U : V->materialized_uses()) {
         if (++NumUses > Record.size())
           break;
         Order[&U] = Record[NumUses - 1];
@@ -5266,7 +5266,8 @@ std::error_code BitcodeReader::materialize(GlobalValue *GV) {
 
   // Upgrade any old intrinsic calls in the function.
   for (auto &I : UpgradedIntrinsics) {
-    for (auto UI = I.first->user_begin(), UE = I.first->user_end(); UI != UE;) {
+    for (auto UI = I.first->materialized_user_begin(), UE = I.first->user_end();
+         UI != UE;) {
       User *U = *UI;
       ++UI;
       if (CallInst *CI = dyn_cast<CallInst>(U))