Restructure inlining of Bigint accessors, use consistent approach, fixes a potential crash.

runtime/lib/bigint.dart

 // Copyright (c) 2014, 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.
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 /*
  * Copyright (c) 2003-2005  Tom Wu
@@ skipping 48 matching lines @@
   // Note: Not declared as final in order to satisfy optimizer, which expects
   // constants to be in canonical form (Smi).
   static _Bigint ZERO = new _Bigint();
   static _Bigint ONE = new _Bigint()._setInt(1);
 
   // Digit conversion table for parsing.
   static final Map<int, int> DIGIT_TABLE = _createDigitTable();
 
   // Internal data structure.
   bool get _neg native "Bigint_getNeg";
-  void set _neg(bool neg) native "Bigint_setNeg";
+  void set _neg(bool value) native "Bigint_setNeg";
   int get _used native "Bigint_getUsed";
-  void set _used(int used) native "Bigint_setUsed";
+  void set _used(int value) native "Bigint_setUsed";
   Uint32List get _digits native "Bigint_getDigits";
   void set _digits(Uint32List digits) {
     // The VM expects digits_ to be a Uint32List.
     assert(digits != null);
     _set_digits(digits);
   }
 
-  void _set_digits(Uint32List digits) native "Bigint_setDigits";
+  void _set_digits(Uint32List value) native "Bigint_setDigits";
 
   // Factory returning an instance initialized to value 0.
   factory _Bigint() native "Bigint_allocate";
 
   // Factory returning an instance initialized to an integer value.
   factory _Bigint._fromInt(int i) {
     return new _Bigint()._setInt(i);
   }
 
   // Factory returning an instance initialized to a hex string.
@@ skipping 1386 matching lines @@
   void _sqrTo(_Bigint x, _Bigint r) {
     x._sqrTo(r);
     _reduce(r);
   }
 
   void _mulTo(_Bigint x, _Bigint y, _Bigint r) {
     x._mulTo(y, r);
     _reduce(r);
   }
 }