Use a uniform way to emit code for all instructions.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index 88557a7a7268a49be896362fa58988d660f7c194..376bafe98ddc38ad41ba54e4084626b1e23aa3dc 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -3832,8 +3832,11 @@ void PolymorphicInstanceCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
 
 LocationSummary* BranchInstr::MakeLocationSummary() const {
-  UNREACHABLE();
-  return NULL;
+  LocationSummary* summary = comparison()->locs();
+  // Share the location summary with the comparison.  Branches don't produce
+  // a result.
+  summary->set_out(Location::NoLocation());
+  return summary;
 }
 
 
@@ -4063,14 +4066,6 @@ LocationSummary* GotoInstr::MakeLocationSummary() const {
 
 
 void GotoInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  if (!compiler->is_optimizing()) {
-    // Add deoptimization descriptor for deoptimizing instructions that may
-    // be inserted before this instruction.
-    compiler->AddCurrentDescriptor(PcDescriptors::kDeopt,
-                                   GetDeoptId(),
-                                   0);  // No token position.
-  }
-
   if (HasParallelMove()) {
     compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
   }