Make line-starts 32-bits TypedData instead of Array of smis.

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 346 matching lines @@
   RawObject* BuildParameterDescriptor(intptr_t kernel_offset);
   RawObject* EvaluateMetadata(intptr_t kernel_offset);
   void CollectTokenPositionsFor(
       intptr_t script_index,
       intptr_t initial_script_index,
       GrowableArray<intptr_t>* record_token_positions_in,
       GrowableArray<intptr_t>* record_yield_positions_in);
   intptr_t SourceTableSize();
   String& SourceTableUriFor(intptr_t index);
   String& GetSourceFor(intptr_t index);
-  Array& GetLineStartsFor(intptr_t index);
+  TypedData& GetLineStartsFor(intptr_t index);
 
  private:
   void DiscoverEnclosingElements(Zone* zone,
                                  const Function& function,
                                  Function* outermost_function);
 
   void ReadUntilFunctionNode();
   StringIndex GetNameFromVariableDeclaration(intptr_t kernel_offset,
                                              const Function& function);
 
@@ skipping 1184 matching lines @@
   const uint8_t* saved_raw_buffer_;
   const TypedData* saved_typed_data_;
   intptr_t saved_offset_;
 };
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 #endif  // RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_