AArch64: Use TTI branch functions in branch relaxation

The main change is to return the code size from
InsertBranch/RemoveBranch.

Patch mostly by Tim Northover

llvm-svn: 281505
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.cpp b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
index 1332258..c73698b 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
@@ -117,9 +117,11 @@
                                      MachineBasicBlock *TBB,
                                      MachineBasicBlock *FBB,
                                      ArrayRef<MachineOperand> Cond,
-                                     const DebugLoc &DL) const {
+                                     const DebugLoc &DL,
+                                     int *BytesAdded) const {
   // Shouldn't be a fall through.
   assert(TBB && "InsertBranch must not be told to insert a fallthrough");
+  assert(!BytesAdded && "code size not handled");
 
   // # of condition operands:
   //  Unconditional branches: 0
@@ -145,7 +147,10 @@
   return 1;
 }
 
-unsigned MipsInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+unsigned MipsInstrInfo::RemoveBranch(MachineBasicBlock &MBB,
+                                     int *BytesRemoved) const {
+  assert(!BytesRemoved && "code size not handled");
+
   MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
   unsigned removed;