[IPO] Avoid repeated hash lookups (NFC) (#107796)

Author: kazutakahirata

llvm/include/llvm/Transforms/IPO/ProfiledCallGraph.h

@@ -156,10 +156,8 @@ class ProfiledCallGraph {
     ProfiledCallGraphEdge Edge(ProfiledFunctions[CallerName],
                                CalleeIt->second, Weight);
     auto &Edges = ProfiledFunctions[CallerName]->Edges;
-    auto EdgeIt = Edges.find(Edge);
-    if (EdgeIt == Edges.end()) {
-      Edges.insert(Edge);
-    } else {
+    auto [EdgeIt, Inserted] = Edges.insert(Edge);
+    if (!Inserted) {
       // Accumulate weight to the existing edge.
       Edge.Weight += EdgeIt->Weight;
       Edges.erase(EdgeIt);