Rename WeakVH to WeakTrackingVH; NFC

This relands r301424.

llvm-svn: 301812
diff --git a/llvm/lib/Analysis/AssumptionCache.cpp b/llvm/lib/Analysis/AssumptionCache.cpp
index 1fae947..0468c79 100644
--- a/llvm/lib/Analysis/AssumptionCache.cpp
+++ b/llvm/lib/Analysis/AssumptionCache.cpp
@@ -29,15 +29,16 @@
                           cl::desc("Enable verification of assumption cache"),
                           cl::init(false));
 
-SmallVector<WeakVH, 1> &AssumptionCache::getOrInsertAffectedValues(Value *V) {
+SmallVector<WeakTrackingVH, 1> &
+AssumptionCache::getOrInsertAffectedValues(Value *V) {
   // Try using find_as first to avoid creating extra value handles just for the
   // purpose of doing the lookup.
   auto AVI = AffectedValues.find_as(V);
   if (AVI != AffectedValues.end())
     return AVI->second;
 
-  auto AVIP = AffectedValues.insert({
-      AffectedValueCallbackVH(V, this), SmallVector<WeakVH, 1>()});
+  auto AVIP = AffectedValues.insert(
+      {AffectedValueCallbackVH(V, this), SmallVector<WeakTrackingVH, 1>()});
   return AVIP.first->second;
 }