Intern globals per-context, not per tree, which allows transitioning between trees that use globals. The type of all global slots compiled code uses is expected to remain stable, otherwise the entire code cache has to be flushed. Changes to the shape of the global object also flush the code cache. Working for trace-tests.js, but fails math-partial-sum.js

js/src/jsbuiltins.cpp

@@ -417,8 +417,6 @@ js_FastCallIteratorNext(JSContext* cx, JSObject* iterobj)
 GuardRecord* FASTCALL
 js_CallTree(InterpState* state, Fragment* f)
 {
-    /* current we can't deal with inner trees that have globals so report an error */
-    JS_ASSERT(!((TreeInfo*)f->vmprivate)->globalSlots.length());
     union { NIns *code; GuardRecord* (FASTCALL *func)(InterpState*, Fragment*); } u;
     u.code = f->code();
     return u.func(state, NULL);