perform EXPORT_ALL on SIDE_MODULEs too (#7319)

This avoids fastcomp doing it internally as a hack, and will allow further improvements for dynamic linking.

Author: kripken

emcc.py

@@ -1162,8 +1162,7 @@ def check(input_file):
         if shared.Settings.EMULATED_FUNCTION_POINTERS == 0:
           shared.Settings.EMULATED_FUNCTION_POINTERS = 2 # by default, use optimized function pointer emulation
         shared.Settings.ERROR_ON_UNDEFINED_SYMBOLS = shared.Settings.WARN_ON_UNDEFINED_SYMBOLS = 0
-        if not shared.Settings.SIDE_MODULE:
-          shared.Settings.EXPORT_ALL = 1
+        shared.Settings.EXPORT_ALL = 1
 
       if shared.Settings.EMTERPRETIFY:
         shared.Settings.FINALIZE_ASM_JS = 0