Serializer: ensure unique script ids when deserializing.

test/mjsunit/debug-breakpoints.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --expose-debug-as debug
 // Get the Debug object exposed from the debug context global object.
 Debug = debug.Debug
 
+Debug.setListener(function() {});
+
 function f() {a=1;b=2}
 function g() {
   a=1;
   b=2;
 }
 
 bp = Debug.setBreakPoint(f, 0, 0);
 assertEquals("() {[B0]a=1;b=2}", Debug.showBreakPoints(f));
 Debug.clearBreakPoint(bp);
 assertEquals("() {a=1;b=2}", Debug.showBreakPoints(f));
@@ skipping 173 matching lines @@
   [16, "f2(1,2),[B0]f3()"],
   [22, "+[B0]f3()"]
 ];
 for(var i = 0; i < scenario.length; i++) {
   bp1 = setBreakpointByPosition(h, scenario[i][0],
       Debug.BreakPositionAlignment.BreakPosition);
   assertTrue(Debug.showBreakPoints(h, undefined,
       Debug.BreakPositionAlignment.BreakPosition).indexOf(scenario[i][1]) > 0);
   Debug.clearBreakPoint(bp1);
 }