[CodeMetrics] use hasOneLiveUse instead of hasOneUse while analyzing inlinable callsites

[sinan]

Summary

It would be better for CodeMetrics to use hasOneLiveUse while analyzing static and called once callsites, since inline cost now uses hasOneLiveUse instead of hasOneUse to avoid overpessimization on dead constant cases (since this patch https://reviews.llvm.org/D109294).

This change has no noticeable influence now, but it helps improve the accuracy of cost models of passes that use CodeMetrics.

[nikic]

LG

[fhahn]

LGTM, thanks!

llvm/lib/Analysis/CodeMetrics.cpp

if (const auto *Call = dyn_cast<CallBase>(&I)) {
       if (const Function *F = Call->getCalledFunction()) {
         bool IsLoweredToCall = TTI.isLoweredToCall(F);
         // If a function is both internal and has a single use, then it is
         // extremely likely to get inlined in the future (it was probably
         // exposed by an interleaved devirtualization pass).
         // When preparing for LTO, liberally consider calls as inline
         // candidates.
         if (!Call->isNoInline() && IsLoweredToCall &&
-            ((F->hasInternalLinkage() && F->hasOneUse()) || PrepareForLTO)) {
+            ((F->hasInternalLinkage() && F->hasOneLiveUse()) ||
+             PrepareForLTO)) {
           ++NumInlineCandidates;
         }
 
         // If this call is to function itself, then the function is recursive.
         // Inlining it into other functions is a bad idea, because this is
         // basically just a form of loop peeling, and our metrics aren't useful
         // for that case.
         if (F == BB->getParent())