Wasm workers

emcc.py

@@ -1431,8 +1431,14 @@ def phase_setup(options, state, newargs, user_settings):
   if settings.USE_PTHREADS or settings.WASM_WORKERS:
     settings.SHARED_MEMORY = 1
 
-  if settings.SHARED_MEMORY and '-pthread' not in newargs:
-    newargs += ['-matomics', '-mbulk-memory']
+  if settings.SHARED_MEMORY:
+    if '-matomics' not in newargs:
+      newargs += ['-matomics']
+    if '-mbulk-memory' not in newargs:
+      newargs += ['-mbulk-memory']
+
+  if settings.USE_PTHREADS and '-pthread' not in newargs:
+    newargs += ['-pthread']
 
   if 'DISABLE_EXCEPTION_CATCHING' in user_settings and 'EXCEPTION_CATCHING_ALLOWED' in user_settings:
     # If we get here then the user specified both DISABLE_EXCEPTION_CATCHING and EXCEPTION_CATCHING_ALLOWED