PNaCl: Add more MIPS support to the toolchain

pnacl/driver/pnacl-ld.py

 #!/usr/bin/python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # IMPORTANT NOTE: If you make local mods to this file, you must run:
 #   %  pnacl/build.sh driver
 # in order for them to take effect in the scons build.  This command
 # updates the copy in the toolchain/ tree.
 #
@@ skipping 71 matching lines @@
   # Add glibc/lib-<arch>/ to the search path.
   # These are here to let the bitcode link find native objects
   # needed by the GLibC toolchain.
   # TODO(pdox): Remove these when we have bitcode .pso stubs for GlibC.
   'SEARCH_DIRS_NATIVE': '${LIBMODE_GLIBC ? ${LIBS_ARCH}/}',
 
   'LIBS_ARCH'        : '${LIBS_%ARCH%}',
   'LIBS_ARM'         : '${BASE_GLIBC}/lib-arm',
   'LIBS_X8632'       : '${BASE_GLIBC}/lib-x86-32',
   'LIBS_X8664'       : '${BASE_GLIBC}/lib-x86-64',
+  'LIBS_MIPS32'      : '${BASE_GLIBC}/lib-mips32',
   # HACK-END
 
   'LD_GOLD_OFORMAT'        : '${LD_GOLD_OFORMAT_%ARCH%}',
   'LD_GOLD_OFORMAT_ARM'    : 'elf32-littlearm',
   'LD_GOLD_OFORMAT_X8632'  : 'elf32-nacl',
   'LD_GOLD_OFORMAT_X8664'  : 'elf64-nacl',
+  'LD_GOLD_OFORMAT_MIPS32' : 'elf32-tradlittlemips',
 
   'BCLD'      : '${LD_GOLD}',
   'BCLD_FLAGS': '--native-client --oformat ${LD_GOLD_OFORMAT} -Ttext=0x20000 ' +
                 '${!SHARED && !RELOCATABLE ? --undef-sym-check} ' +
                 '${GOLD_PLUGIN_ARGS} ${LD_FLAGS}',
   'RUN_BCLD': ('${BCLD} ${BCLD_FLAGS} ${inputs} -o ${output}'),
 }
 
 def AddToBCLinkFlags(*args):
   env.append('LD_FLAGS', *args)
@@ skipping 327 matching lines @@
   RunDriver('translate', args)
 
 def LinkBC(inputs, output):
   '''Input: a bunch of bc/o/lib input files
      Output: a combined & optimized bitcode file
   '''
   # Produce combined bitcode file
   RunWithEnv('${RUN_BCLD}',
              inputs=inputs,
              output=output)