Switch more loops to be range-based

This makes the code a little more concise, no functional change is
intended.

llvm-svn: 273644
diff --git a/llvm/lib/Transforms/Scalar/Float2Int.cpp b/llvm/lib/Transforms/Scalar/Float2Int.cpp
index bf37aa0..2ddc543 100644
--- a/llvm/lib/Transforms/Scalar/Float2Int.cpp
+++ b/llvm/lib/Transforms/Scalar/Float2Int.cpp
@@ -246,7 +246,7 @@
 // Walk forwards down the list of seen instructions, so we visit defs before
 // uses.
 void Float2Int::walkForwards() {
-  for (auto &It : make_range(SeenInsts.rbegin(), SeenInsts.rend())) {
+  for (auto &It : reverse(SeenInsts)) {
     if (It.second != unknownRange())
       continue;
 
@@ -511,7 +511,7 @@
 
 // Perform dead code elimination on the instructions we just modified.
 void Float2Int::cleanup() {
-  for (auto &I : make_range(ConvertedInsts.rbegin(), ConvertedInsts.rend()))
+  for (auto &I : reverse(ConvertedInsts))
     I.first->eraseFromParent();
 }