[kernel] Add fileOffset on FunctionExpression

runtime/vm/kernel_binary_flowgraph.h

 // Copyright (c) 2017, 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.
 
 #ifndef RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_
 #define RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
 
 #include <map>
@@ skipping 971 matching lines @@
       case kType:
         builder_->SkipDartType();  // read type.
         if (++next_read_ == field) return;
       case kInitializer:
         if (builder_->ReadTag() == kSomething) {
           if (detect_function_literal_initializer &&
               builder_->PeekTag() == kFunctionExpression) {
             AlternativeReadingScope alt(builder_->reader_);
             Tag tag = builder_->ReadTag();
             ASSERT(tag == kFunctionExpression);
+            builder_->ReadPosition();  // read position.
 
             FunctionNodeHelper helper(builder_);
             helper.ReadUntilIncluding(FunctionNodeHelper::kEndPosition);
 
             has_function_literal_initializer_ = true;
             function_literal_start_ = helper.position_;
             function_literal_end_ = helper.end_position_;
           }
           builder_->SkipExpression();  // read initializer.
         }
@@ skipping 564 matching lines @@
  private:
   StreamingFlowGraphBuilder* builder_;
   intptr_t next_read_;
 };
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 #endif  // RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_