Implement experimental exponentiation operator

src/compiler/ast-graph-builder.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/linkage.h"
@@ skipping 2887 matching lines @@
       break;
     case Token::MUL:
       js_op = javascript()->Multiply();
       break;
     case Token::DIV:
       js_op = javascript()->Divide();
       break;
     case Token::MOD:
       js_op = javascript()->Modulus();
       break;
+    case Token::EXP:
+      js_op = javascript()->Exponentiate();
+      break;
     default:
       UNREACHABLE();
       js_op = NULL;
   }
   return NewNode(js_op, left, right);
 }
 
 
 Node* AstGraphBuilder::BuildStackCheck() {
   IfBuilder stack_check(this);
@@ skipping 315 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8