Fix test_pthread_run_script, and add a ChangeLog entry.

Author: juj

ChangeLog.md

@@ -17,6 +17,8 @@ See docs/process.md for how version tagging works.
 
 Current Trunk
 -------------
+- Removed preamble variable ENVIRONMENT_IS_PTHREAD. Use the variable
+  ENVIRONMENT_IS_WORKER instead to detect code that is running in a pthread.
 - All ports now install their headers into a shared directory under
   `EM_CACHE`.  This should not really be a user visible change although one
   side effect is that once a give ports is built its headers are then

tests/pthread/test_pthread_run_script.cpp

@@ -19,7 +19,11 @@ void EMSCRIPTEN_KEEPALIVE FinishTest(int result)
 void TestAsyncRunScript()
 {
   // 5. Test emscripten_async_run_script() runs in a worker.
+#if __EMSCRIPTEN_PTHREADS__
+  emscripten_async_run_script("Module['_FinishTest'](ENVIRONMENT_IS_WORKER);", 1);
+#else
   emscripten_async_run_script("Module['_FinishTest'](!ENVIRONMENT_IS_WORKER);", 1);
+#endif
 }
 
 void AsyncScriptLoaded()