Update fixmes

Extending beyond the limitations of `getExpectedExitLoopLatchBranch`
is a possible improvement for the future not an urgent fixme.

No one has pointed out code that computes estimated trip counts
without using `llvm::getLoopEstimatedTripCount`.

Author: jdenny-ornl

llvm/lib/Transforms/Utils/LoopPeel.cpp

@@ -1219,7 +1219,7 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, bool PeelLast, LoopInfo *LI,
   // while examining it in isolation without considering the probability of
   // actually reaching it, we store the new trip count as separate metadata.
   //
-  // FIXME: getLoopEstimatedTripCount and setLoopEstimatedTripCount skip loops
+  // TODO: getLoopEstimatedTripCount and setLoopEstimatedTripCount skip loops
   // that don't match the restrictions of getExpectedExitLoopLatchBranch in
   // LoopUtils.cpp.  For example,
   // llvm/tests/Transforms/LoopUnroll/peel-branch-weights.ll (introduced by

llvm/lib/Transforms/Utils/LoopUtils.cpp

@@ -866,10 +866,6 @@ llvm::getLoopEstimatedTripCount(Loop *L,
             getEstimatedTripCount(LatchBranch, L, ExitWeight)) {
       if (EstimatedLoopInvocationWeight)
         *EstimatedLoopInvocationWeight = ExitWeight;
-      // FIXME: Where else are branch weights directly used for estimating loop
-      // trip counts?  They should also be updated to use
-      // LLVMLoopEstimatedTripCount when present... or to just call this
-      // function.
       if (auto EstimatedTripCount =
               getOptionalIntLoopAttribute(L, LLVMLoopEstimatedTripCount))
         return EstimatedTripCount;