Simplify known successor block lowering.

src/arm64/lithium-arm64.cc

Index: src/arm64/lithium-arm64.cc
diff --git a/src/arm64/lithium-arm64.cc b/src/arm64/lithium-arm64.cc
index d365dcf96cf29faf0e33c1e80b3906b0abb4fd63..db284632aaf4feab162b4c5ac93928ec2c31f296 100644
--- a/src/arm64/lithium-arm64.cc
+++ b/src/arm64/lithium-arm64.cc
@@ -672,7 +672,14 @@ void LChunkBuilder::VisitInstruction(HInstruction* current) {
       chunk_->AddInstruction(dummy, current_block_);
     }
   } else {
-    instr = current->CompileToLithium(this);
+    HBasicBlock* successor;
+    if (current->IsControlInstruction() &&
+        HControlInstruction::cast(current)->KnownSuccessorBlock(&successor) &&
+        successor != NULL) {
+      instr = new(zone()) LGoto(successor);
+    } else {
+      instr = current->CompileToLithium(this);
+    }
   }
 
   argument_count_ += current->argument_delta();
@@ -972,9 +979,6 @@ LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
 
 
 LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
-
   HValue* value = instr->value();
   Representation r = value->representation();
   HType type = value->type();
@@ -1259,8 +1263,6 @@ LInstruction* LChunkBuilder::DoClassOfTestAndBranch(
 
 LInstruction* LChunkBuilder::DoCompareNumericAndBranch(
     HCompareNumericAndBranch* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
   Representation r = instr->representation();
   if (r.IsSmiOrInteger32()) {
     ASSERT(instr->left()->representation().Equals(r));
@@ -1311,9 +1313,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 
 LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
     HCompareObjectEqAndBranch* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
-
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterAtStart(instr->right());
   return new(zone()) LCmpObjectEqAndBranch(left, right);
@@ -1321,9 +1320,6 @@ LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
 
 
 LInstruction* LChunkBuilder::DoCompareMap(HCompareMap* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
-
   ASSERT(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());
   LOperand* temp = TempRegister();
@@ -1577,8 +1573,6 @@ LInstruction* LChunkBuilder::DoIsConstructCallAndBranch(
 
 LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
     HCompareMinusZeroAndBranch* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
   LOperand* value = UseRegister(instr->value());
   LOperand* scratch = TempRegister();
   return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
@@ -2555,9 +2549,6 @@ LInstruction* LChunkBuilder::DoTypeof(HTypeof* instr) {
 
 
 LInstruction* LChunkBuilder::DoTypeofIsAndBranch(HTypeofIsAndBranch* instr) {
-  LInstruction* goto_instr = CheckElideControlInstruction(instr);
-  if (goto_instr != NULL) return goto_instr;
-
   // We only need temp registers in some cases, but we can't dereference the
   // instr->type_literal() handle to test that here.
   LOperand* temp1 = TempRegister();