Add cwrap to EXTRA_EXPORTED_RUNTIME_METHODS

(cherry picked from commit d2c34e83b5851e9290e20ef383409a3c5adc16d6)

platform/javascript/detect.py

@@ -227,7 +227,7 @@ def configure(env):
     env.Append(LINKFLAGS=["-s", "OFFSCREEN_FRAMEBUFFER=1"])
 
     # callMain for manual start.
-    env.Append(LINKFLAGS=["-s", "EXTRA_EXPORTED_RUNTIME_METHODS=['callMain']"])
+    env.Append(LINKFLAGS=["-s", "EXTRA_EXPORTED_RUNTIME_METHODS=['callMain','cwrap']"])
 
     # Add code that allow exiting runtime.
     env.Append(LINKFLAGS=["-s", "EXIT_RUNTIME=1"])