[turbofan] Introduce prediction for exception handlers.

src/compiler/ast-graph-builder.h

 // 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.
 
 #ifndef V8_COMPILER_AST_GRAPH_BUILDER_H_
 #define V8_COMPILER_AST_GRAPH_BUILDER_H_
 
 #include "src/ast.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/liveness-analyzer.h"
@@ skipping 72 matching lines @@
   ControlScope* execution_control_;
 
   // Stack of context objects pushed onto the chain by the visitor.
   ContextScope* execution_context_;
 
   // Nodes representing values in the activation record.
   SetOncePointer<Node> function_closure_;
   SetOncePointer<Node> function_context_;
 
   // Tracks how many try-blocks are currently entered.
+  int try_catch_nesting_level_;
   int try_nesting_level_;
 
   // Temporary storage for building node input lists.
   int input_buffer_size_;
   Node** input_buffer_;
 
   // Control nodes that exit the function body.
   ZoneVector<Node*> exit_controls_;
 
   // Result of loop assignment analysis performed before graph creation.
@@ skipping 402 matching lines @@
 
   // Prepare environment to be used as loop header.
   void PrepareForLoop(BitVector* assigned, bool is_osr = false);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_AST_GRAPH_BUILDER_H_