[IRTranslator] Update getOrCreateBB API to use references.
A null basic block is invalid, so just pass a reference.

llvm-svn: 263260
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 4ba21e7..3e0c0ec 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -51,8 +51,8 @@
   return ValReg;
 }
 
-MachineBasicBlock &IRTranslator::getOrCreateBB(const BasicBlock *BB) {
-  MachineBasicBlock *&MBB = BBToMBB[BB];
+MachineBasicBlock &IRTranslator::getOrCreateBB(const BasicBlock &BB) {
+  MachineBasicBlock *&MBB = BBToMBB[&BB];
   if (!MBB) {
     MachineFunction &MF = MIRBuilder.getMF();
     MBB = MF.CreateMachineBasicBlock();
@@ -111,7 +111,7 @@
   MIRBuilder.setFunction(MF);
   MRI = &MF.getRegInfo();
   // Setup the arguments.
-  MachineBasicBlock &MBB = getOrCreateBB(&F.front());
+  MachineBasicBlock &MBB = getOrCreateBB(F.front());
   MIRBuilder.setBasicBlock(MBB);
   SmallVector<unsigned, 8> VRegArgs;
   for (const Argument &Arg: F.args())
@@ -122,7 +122,7 @@
     report_fatal_error("Unable to lower arguments");
 
   for (const BasicBlock &BB: F) {
-    MachineBasicBlock &MBB = getOrCreateBB(&BB);
+    MachineBasicBlock &MBB = getOrCreateBB(BB);
     MIRBuilder.setBasicBlock(MBB);
     for (const Instruction &Inst: BB) {
       bool Succeeded = translate(Inst);