Restore metadce testing and update it (#10796)

Author: kripken

tests/other/metadce/hello_world_O3_MAIN_MODULE_2.imports

@@ -4,7 +4,6 @@ __table_base
 emscripten_memcpy_big
 emscripten_resize_heap
 fd_write
-fp$__stdio_write$iiii
 g$stdout
 memory
 table

tests/other/metadce/hello_world_O3_MAIN_MODULE_2.sent

@@ -4,7 +4,6 @@ __table_base
 emscripten_memcpy_big
 emscripten_resize_heap
 fd_write
-fp$__stdio_write$iiii
 g$stdout
 memory
 table

tests/test_other.py

@@ -8336,8 +8336,7 @@ def test_metadce_cxx_fastcomp(self, *args):
     # don't compare the # of functions in a main module, which changes a lot
     # TODO(sbc): Investivate why the number of exports is order of magnitude
     # larger for wasm backend.
-    # FIXME disabled temporarily for rolling
-    # 'main_module_2': (['-O3', '-s', 'MAIN_MODULE=2'], [], [],  10652, True, True, True, False), # noqa
+    'main_module_2': (['-O3', '-s', 'MAIN_MODULE=2'], [], [],  10652, True, True, True, False), # noqa
   })
   @no_fastcomp()
   def test_metadce_hello(self, *args):