Subzero: Cleanly implement register allocation after phi lowering.

src/IceTargetLoweringMIPS32.cpp

Index: src/IceTargetLoweringMIPS32.cpp
diff --git a/src/IceTargetLoweringMIPS32.cpp b/src/IceTargetLoweringMIPS32.cpp
index add97b36dd8abcae2d278ed6e015442ee380b2d1..99c992827475a222248838f4f07d062e42dd367f 100644
--- a/src/IceTargetLoweringMIPS32.cpp
+++ b/src/IceTargetLoweringMIPS32.cpp
@@ -648,15 +648,6 @@ void TargetMIPS32::prelowerPhis() {
   UnimplementedError(Func->getContext()->getFlags());
 }
 
-// Lower the pre-ordered list of assignments into mov instructions.
-// Also has to do some ad-hoc register allocation as necessary.
-void TargetMIPS32::lowerPhiAssignments(CfgNode *Node,
-                                       const AssignList &Assignments) {
-  (void)Node;
-  (void)Assignments;
-  UnimplementedError(Func->getContext()->getFlags());
-}
-
 void TargetMIPS32::postLower() {
   if (Ctx->getFlags().getOptLevel() == Opt_m1)
     return;