Revert "[Inliner] Fix bugs for partial inlining with vector"

This reverts commit 0a5e572,
since I forgot to start a pull request.

Author: joshua-arch1

llvm/lib/Transforms/IPO/PartialInlining.cpp

@@ -1308,8 +1308,8 @@ bool PartialInlinerImpl::tryPartialInline(FunctionCloner &Cloner) {
   InstructionCost SizeCost = std::get<0>(OutliningCosts);
   InstructionCost NonWeightedRcost = std::get<1>(OutliningCosts);
 
-  if (!SizeCost.isValid() || !NonWeightedRcost.isValid())
-    return false;
+  assert(SizeCost.isValid() && NonWeightedRcost.isValid() &&
+         "Expected valid costs");
 
   // Only calculate RelativeToEntryFreq when we are doing single region
   // outlining.