[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/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 2ade6ab1c83..6c5a5ab9ea5 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -358,8 +358,7 @@ static MachineBasicBlock *LowerFPToInt(MachineInstr &MI, DebugLoc DL,
   F->insert(It, DoneMBB);
 
   // Transfer the remainder of BB and its successor edges to DoneMBB.
-  DoneMBB->splice(DoneMBB->begin(), BB,
-                  std::next(MachineBasicBlock::iterator(MI)), BB->end());
+  DoneMBB->splice(DoneMBB->begin(), BB, std::next(MI.getIterator()), BB->end());
   DoneMBB->transferSuccessorsAndUpdatePHIs(BB);
 
   BB->addSuccessor(TrueMBB);