Start inferring return types for static functions

lib/compiler/implementation/ssa/builder.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 Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2347 matching lines @@
     var inputs = <HInstruction>[];
     inputs.add(target);
     if (element.kind == ElementKind.FUNCTION) {
       bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
                                                     element, inputs);
       if (!succeeded) {
         // TODO(ngeoffray): Match the VM behavior and throw an
         // exception at runtime.
         compiler.cancel('Unimplemented non-matching static call', node: node);
       }
-      pushWithPosition(new HInvokeStatic(inputs), node);
+      HInvokeStatic instruction = new HInvokeStatic(inputs);
+      HType returnType =
+          builder.backend.optimisticReturnTypesWithRecompilationOnTypeChange(
+              work.element, element);
+      if (returnType != null) instruction.guaranteedType = returnType;
+      pushWithPosition(instruction, node);
     } else {
       if (element.kind == ElementKind.GETTER) {
         target = new HInvokeStatic(inputs);
         add(target);
         inputs = <HInstruction>[target];
       }
       addDynamicSendArgumentsToList(node, inputs);
       pushWithPosition(new HInvokeClosure(selector, inputs), node);
     }
   }
@@ skipping 842 matching lines @@
         }
         else {
           VariableDefinitions declaration = catchBlock.formals.nodes.head;
           HInstruction condition = null;
           if (declaration.type == null) {
             condition = graph.addConstantBool(true);
             stack.add(condition);
           } else {
             // TODO(aprelev@gmail.com): Once old catch syntax is removed
             // "if" condition above and this "else" branch should be deleted as
-            // type of declared variable won't matter for the catch 
+            // type of declared variable won't matter for the catch
             // condition
             Type type = elements.getType(declaration.type);
             if (type == null) {
               compiler.cancel('Catch with unresolved type', node: catchBlock);
             }
             condition = new HIs(type, unwrappedException, nullOk: true);
             push(condition);
           }
         }
       }
@@ skipping 383 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }