update comment

Created using spr 1.3.4

Author: aaupov

bolt/lib/Core/BinaryFunctionCallGraph.cpp

@@ -252,6 +252,8 @@ buildCallGraph(BinaryContext &BC, CgFilterFunction Filter, bool CgFromPerfData,
 
         for (MCInst &Inst : *BB) {
           // Find call instructions and extract target symbols from each one.
+          // Check CallProfile annotation if the instruction is not recognized
+          // as a call, e.g. unknown control flow indirect jump.
           if (BC.MIB->isCall(Inst) ||
               BC.MIB->hasAnnotation(Inst, "CallProfile")) {
             const CallInfoTy CallInfo = getCallInfo(BB, Inst);