Fix spurious debug-script assertion after enabling Symbols

This approach, of allowing either N or N+1 in this assert,
is the same approach used before my Symbols patch that naively
changed to use assertEquals.

TBR=dslomov@chromium.org

Review URL: https://codereview.chromium.org/439833002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22834 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/debug-script.js

@@ -59,7 +59,7 @@ for (i = 0; i < scripts.length; i++) {
 }
 
 // This has to be updated if the number of native scripts change.
-assertEquals(21, named_native_count);
+assertTrue(named_native_count == 20 || named_native_count == 21);
 // Only the 'gc' extension is loaded.
 assertEquals(1, extension_count);
 // This script and mjsunit.js has been loaded.  If using d8, d8 loads