Move array and string related HType from const to a field in the backend.

sdk/lib/_internal/compiler/implementation/ssa/codegen_helpers.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 /**
  * Instead of emitting each SSA instruction with a temporary variable
  * mark instructions that can be emitted at their use-site.
  * For example, in:
  *   t0 = 4;
  *   t1 = 3;
  *   t2 = add(t0, t1);
  * t0 and t1 would be marked and the resulting code would then be:
  *   t2 = add(4, 3);
  */
 class SsaInstructionMerger extends HBaseVisitor {
+  final Compiler compiler;
   /**
    * List of [HInstruction] that the instruction merger expects in
    * order when visiting the inputs of an instruction.
    */
   List<HInstruction> expectedInputs;
   /**
    * Set of pure [HInstruction] that the instruction merger expects to
    * find. The order of pure instructions do not matter, as they will
    * not be affected by side effects.
    */
   Set<HInstruction> pureInputs;
   Set<HInstruction> generateAtUseSite;
 
   void markAsGenerateAtUseSite(HInstruction instruction) {
     assert(!instruction.isJsStatement());
     generateAtUseSite.add(instruction);
   }
 
-  SsaInstructionMerger(this.generateAtUseSite);
+  SsaInstructionMerger(this.generateAtUseSite, this.compiler);
 
   void visitGraph(HGraph graph) {
     visitDominatorTree(graph);
   }
 
   void analyzeInputs(HInstruction user, int start) {
     List<HInstruction> inputs = user.inputs;
     for (int i = start; i < inputs.length; i++) {
       HInstruction input = inputs[i];
       if (!generateAtUseSite.contains(input)
@@ skipping 50 matching lines @@
   // A type guard should not generate its input at use site, otherwise
   // they would not be alive.
   void visitTypeGuard(HTypeGuard instruction) {}
 
   // An identity operation must only have its inputs generated at use site if
   // does not require an expression with multiple uses (because of null /
   // undefined).
   void visitIdentity(HIdentity instruction) {
     HInstruction left = instruction.left;
     HInstruction right = instruction.right;
-    if (singleIdentityComparison(left, right) != null) {
+    if (singleIdentityComparison(left, right, compiler) != null) {
       super.visitIdentity(instruction);
     }
     // Do nothing.
   }
 
   void visitTypeConversion(HTypeConversion instruction) {
     if (!instruction.isChecked) {
       markAsGenerateAtUseSite(instruction);
     } else if (!instruction.isArgumentTypeCheck
                && !instruction.isReceiverTypeCheck) {
@@ skipping 260 matching lines @@
     }
 
     // If [thenInput] is defined in the first predecessor, then it is only used
     // by [phi] and can be generated at use site.
     if (identical(thenInput.block, end.predecessors[0])) {
       assert(thenInput.usedBy.length == 1);
       markAsGenerateAtUseSite(thenInput);
     }
   }
 }