RefreshCallGraph does not modify the SCC, adding "const" to make it clear (NFC)

llvm-svn: 278037
diff --git a/llvm/lib/Analysis/CallGraphSCCPass.cpp b/llvm/lib/Analysis/CallGraphSCCPass.cpp
index b1e81a4..34dc88e 100644
--- a/llvm/lib/Analysis/CallGraphSCCPass.cpp
+++ b/llvm/lib/Analysis/CallGraphSCCPass.cpp
@@ -100,7 +100,7 @@
   bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
                     CallGraph &CG, bool &CallGraphUpToDate,
                     bool &DevirtualizedCall);
-  bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG,
+  bool RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
                         bool IsCheckingMode);
 };
 
@@ -175,8 +175,8 @@
 /// a function pass like GVN optimizes away stuff feeding the indirect call.
 /// This never happens in checking mode.
 ///
-bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
-                                     CallGraph &CG, bool CheckingMode) {
+bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
+                                     bool CheckingMode) {
   DenseMap<Value*, CallGraphNode*> CallSites;
   
   DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()