Issue 4991 - [emscripten] Update to Emscripten 1.37.3

compile

 #!/usr/bin/env python
 
 import json
 import os
 import re
 import subprocess
 import warnings
 
 EMSCRIPTEN_PATH = '../emscripten'
 SOURCE_DIR = './compiled'
 SOURCE_FILES = [
   os.path.join(path, f)
   for (path, dirs, files) in os.walk(SOURCE_DIR)
   for f in files
   if f.endswith('.cpp')
 ]
 BINDINGS_FILE = os.path.join(SOURCE_DIR, 'bindings.cpp')
 BINDINGS_GENERATOR = os.path.join(SOURCE_DIR, 'bindings.cpp.js')
 BINDINGS_OUTPUT = os.path.join(SOURCE_DIR, 'bindings.js')
 COMPILER_OUTPUT = './lib/compiled.js'
 GENERATION_PARAMS = {
   'SHELL_FILE': "'%s'" % os.path.abspath(os.path.join(SOURCE_DIR, 'shell.js')),
   'ASM_JS': 2,  # "almost asm"
   'TOTAL_MEMORY': 16*1024*1024,
   'TOTAL_STACK': 1*1024*1024,
   'ALLOW_MEMORY_GROWTH': 1,
   'NO_EXIT_RUNTIME': 1,
   'NO_DYNAMIC_EXECUTION': 1,
-  'NO_BROWSER': 1,
   'NO_FILESYSTEM': 1,
   'INVOKE_RUN': 0,
-  'NODE_STDOUT_FLUSH_WORKAROUND': 0,
+  'TEXTDECODER': 0,

[Wladimir Palant, 2017/03/15 11:02:48]

TextDecoder is only used for functions that aren't being called anyway in our
case. Fallback code is being added regardless, so disabling TextDecoder reduces
code size a bit.

+  'EXPORTED_RUNTIME_METHODS': ['cwrap', 'ccall', 'stringToAscii'],

[Wladimir Palant, 2017/03/15 11:02:48]

This reduces code size a bit, almost no functions exported by default are being
used.

 }
 DEFINES = []
 ADDITIONAL_PARAMS = ['-O3', '-m32', '-std=gnu++14', '--memory-init-file', '0',
     '--emit-symbol-map']
 
 def getenv():
   path = []
   env = {}
   output = subprocess.check_output([
       '/bin/bash', '-c', os.path.join(EMSCRIPTEN_PATH, 'emsdk_env.sh')])
@@ skipping 28 matching lines @@
   params.extend('-D' + flag for flag in DEFINES)
   for key, value in GENERATION_PARAMS.iteritems():
     params.extend(['-s', '%s=%s' % (key, str(value))])
   params.extend(ADDITIONAL_PARAMS)
   subprocess.check_call(params, env=env)
 
 if __name__ == '__main__':
   env = getenv()
   generate_bindings(env)
   run_compiler(env)