[WebAssembly] Simplify iterator navigations (NFC)

Summary:
- Replaces some uses of `MachineFunction::iterator(MBB)` with
  `MBB->getIterator()` and `MachineBasicBlock::iterator(MI)` with
  `MI->getIterator()`, which are simpler.
- Replaces some uses of `std::prev` of `std::next` that takes a
  MachineFunction or MachineBasicBlock iterator with `getPrevNode` and
  `getNextNode`, which are also simpler.

Reviewers: sbc100

Subscribers: dschuff, sunfish, jgravelle-google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58913

llvm-svn: 355444

1 files changed, 1 insertions, 2 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
index 17fb8e1..f648154 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
@@ -319,8 +319,7 @@ bool LoopFixer::run() {
 
       // This is a successor we need to rewrite.
       MachineBasicBlock *Split = MF.CreateMachineBasicBlock();
-      MF.insert(MBB->isLayoutSuccessor(Succ) ? MachineFunction::iterator(Succ)
-                                             : MF.end(),
+      MF.insert(MBB->isLayoutSuccessor(Succ) ? Succ->getIterator() : MF.end(),
                 Split);
       MLI.changeLoopFor(Split, Loop);