Declare parameters of the bailout version in beginGraph, instead of setting them up in endGraph.

lib/compiler/implementation/ssa/bailout.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.
 
 class BailoutInfo {
   int instructionId;
   int bailoutId;
   BailoutInfo(this.instructionId, this.bailoutId);
 }
 
@@ skipping 353 matching lines @@
  * Propagates bailout information to blocks that need it. This visitor
  * is run before codegen, to know which blocks have to deal with
  * bailouts.
  */
 class SsaBailoutPropagator extends HBaseVisitor {
   final Compiler compiler;
   final List<HBasicBlock> blocks;
   final List<HLabeledBlockInformation> labeledBlockInformations;
   final Set<HInstruction> generateAtUseSite;
   SubGraph subGraph;
+  int maxBailoutParameters = 0;
 
   /**
    * If set to true, the graph has either multiple bailouts in
    * different places, or a bailout inside an if or a loop. For such a
    * graph, the code generator will emit a generic switch.
    */
   bool hasComplexTypeGuards = false;
 
   /**
    * The first type guard in the graph.
@@ skipping 117 matching lines @@
     visitBasicBlock(branchBlock.successors[1]);
     // With labeled breaks we can have more dominated blocks.
     if (dominated.length >= 3) {
       for (int i = 2; i < dominated.length; i++) {
         visitBasicBlock(dominated[i]);
       }
     }
   }
 
   visitTypeGuard(HTypeGuard guard) {
+    int inputLength = guard.inputs.length;
+    if (inputLength > maxBailoutParameters) {
+      maxBailoutParameters = inputLength;
+    }
     if (blocks.isEmpty()) {
       if (firstTypeGuard === null || firstTypeGuard.state === guard.state) {
         firstTypeGuard = guard;
       } else {
         hasComplexTypeGuards = true;
       }
     } else {
       hasComplexTypeGuards = true;
       blocks.forEach((HBasicBlock block) {
         block.guards.add(guard);
       });
     }
   }
 }