run js opts for safe heap

emcc

@@ -1223,7 +1223,8 @@ try:
     assert not shared.Settings.PGO, 'cannot run PGO in ASM_JS mode'
 
     if shared.Settings.SAFE_HEAP and not js_opts:
-      logging.warning('asm.js+SAFE_HEAP requires js opts to be run to be fully effective (-O2 or above by default)')
+      js_opts = True
+      logging.warning('enabling js opts to allow SAFE_HEAP to work properly')
 
     if shared.Settings.ALLOW_MEMORY_GROWTH:
       logging.error('Cannot enable ALLOW_MEMORY_GROWTH with asm.js, build with -s ASM_JS=0 if you need a growable heap');
@@ -1998,12 +1999,12 @@ try:
       else:
         return 'eliminate'
 
-    js_optimizer_queue += [get_eliminate()]
-
-    if shared.Settings.AGGRESSIVE_VARIABLE_ELIMINATION:
-      js_optimizer_queue += ['aggressiveVariableElimination']
-
     if opt_level >= 2:
+      js_optimizer_queue += [get_eliminate()]
+
+      if shared.Settings.AGGRESSIVE_VARIABLE_ELIMINATION:
+        js_optimizer_queue += ['aggressiveVariableElimination']
+
       js_optimizer_queue += ['simplifyExpressions']
 
   if closure and not shared.Settings.ASM_JS:
@@ -2022,13 +2023,13 @@ try:
       js_optimizer_queue += ['outline']
       js_optimizer_extra_info['sizeToOutline'] = shared.Settings.OUTLINING_LIMIT
 
-    if (not closure or shared.Settings.ASM_JS) and shared.Settings.RELOOP and debug_level < 3:
+    if opt_level >= 2 and (not closure or shared.Settings.ASM_JS) and shared.Settings.RELOOP and debug_level < 3:
       if shared.Settings.ASM_JS and opt_level >= 3 and shared.Settings.OUTLINING_LIMIT == 0:
         js_optimizer_queue += ['registerizeHarder']
       else:
         js_optimizer_queue += ['registerize']
 
-    if opt_level > 0:
+    if opt_level >= 2:
       if debug_level < 2 and shared.Settings.ASM_JS: js_optimizer_queue += ['minifyNames']
       if debug_level == 0: js_optimizer_queue += ['minifyWhitespace']