[CodeGenPrepare][NFC] Update the dominator tree instead of rebuilding it

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D153638

Author: momchil-velikov

llvm/include/llvm/Transforms/Utils/BypassSlowDivision.h

@@ -25,6 +25,8 @@
 namespace llvm {
 
 class BasicBlock;
+class DomTreeUpdater;
+class LoopInfo;
 class Value;
 
 struct DivRemMapKey {
@@ -66,8 +68,9 @@ template <> struct DenseMapInfo<DivRemMapKey> {
 ///
 /// This optimization may add basic blocks immediately after BB; for obvious
 /// reasons, you shouldn't pass those blocks to bypassSlowDivision.
-bool bypassSlowDivision(
-    BasicBlock *BB, const DenseMap<unsigned int, unsigned int> &BypassWidth);
+bool bypassSlowDivision(BasicBlock *BB,
+                        const DenseMap<unsigned int, unsigned int> &BypassWidth,
+                        DomTreeUpdater *DTU = nullptr, LoopInfo *LI = nullptr);
 
 } // end namespace llvm