[debugger] correctly find source position of implicit return statement.

test/mjsunit/mirror-script.js

Index: test/mjsunit/mirror-script.js
diff --git a/test/mjsunit/mirror-script.js b/test/mjsunit/mirror-script.js
index e545a61637244ba3ce85eaefabd8b80e43f6d02c..7642839d5327e73d9a9175c61e49e66a8f017904 100644
--- a/test/mjsunit/mirror-script.js
+++ b/test/mjsunit/mirror-script.js
@@ -83,7 +83,7 @@ function testScriptMirror(f, file_name, file_lines, type, compilation_type,
 
 
 // Test the script mirror for different functions.
-testScriptMirror(function(){}, 'mirror-script.js', 98, 2, 0);
+testScriptMirror(function(){}, 'mirror-script.js', 99, 2, 0);
 testScriptMirror(Math.round, 'native math.js', -1, 0, 0);
 testScriptMirror(eval('(function(){})'), null, 1, 2, 1, '(function(){})', 87);
 testScriptMirror(eval('(function(){\n  })'), null, 2, 2, 1, '(function(){\n  })', 88);