Adds deprecation messages for MIPS cross-builds

tools/build.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 #
 
 import optparse
 import os
 import re
@@ skipping 81 matching lines @@
 
 
 def ProcessOsOption(os_name):
   if os_name == 'host':
     return HOST_OS
   return os_name
 
 
 def ProcessOptions(options, args):
   if options.arch == 'all':
-    options.arch = 'ia32,x64,simarm,simarm64,simmips,simdbc64'
+    options.arch = 'ia32,x64,simarm,simarm64,simdbc64'
   if options.mode == 'all':
     options.mode = 'debug,release,product'
   if options.os == 'all':
     options.os = 'host,android'
   options.mode = options.mode.split(',')
   options.arch = options.arch.split(',')
   options.os = options.os.split(',')
   if not options.gyp and options.toolchain != None:
     print "The --toolchain flag is only supported by the gyp build."
     print "When using the GN build, set the toolchain and sysroot using gn.py."
@@ skipping 364 matching lines @@
       # If we couldn't ensure that goma is started, let the build start, but
       # slowly so we can see any helpful error messages that pop out.
       command += ['-j1']
   command += [target]
   return command
 
 
 filter_xcodebuild_output = False
 def BuildOneConfig(options, target, target_os, mode, arch):
   global filter_xcodebuild_output
+  if arch.startswith('mips'):
+    bold  = '\033[1m'
+    reset = '\033[0m'
+    print(bold + "Warning: MIPS architectures are unlikely to be supported in "
+          "upcoming releases. Please consider using another architecture "
+          "and/or file an issue explaining your specific use of and need for "
+          "MIPS support." + reset)
   start_time = time.time()
   args = []
   build_config = utils.GetBuildConf(mode, arch, target_os)
   if not options.gyp:
     args = BuildNinjaCommand(options, target, target_os, mode, arch)
   else:
     os.environ['DART_BUILD_MODE'] = mode
     if HOST_OS == 'macos':
       filter_xcodebuild_output = True
       project_file = 'dart.xcodeproj'
@@ skipping 112 matching lines @@
         for arch in options.arch:
           if BuildOneConfig(options, target, target_os,
                             mode, arch) != 0:
             return 1
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main())