Roll UPSTREAM_REV and make other changes needed to bring in CL:

pnacl/driver/pnacl-ld.py

 #!/usr/bin/python
 # Copyright (c) 2011 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:
 #   %  tools/llvm/utman.sh driver
 # in order for them to take effect in the scons build.  This command
 # updates the copy in the toolchain/ tree.
 #
@@ skipping 27 matching lines @@
   # This is used during pso -> so translation to set the
   # correct dependencies on the generated ELF file.
   'LIBDEPS'  : '',
 
   'SHARED'   : '0',
   'STATIC'   : '0',
   'PIC'      : '0',
   'STDLIB'   : '1',
   'RELOCATABLE': '0',
 
-  'BAREBONES_LINK' : '0',
-
   'STRIP_MODE' : 'none',
 
   'STRIP_FLAGS'      : '${STRIP_FLAGS_%STRIP_MODE%}',
   'STRIP_FLAGS_all'  : '-s',
   'STRIP_FLAGS_debug': '-S',
 
   'PNACL_TRANSLATE_FLAGS': '${PIC ? -fPIC}',
 
   'OPT_FLAGS': '-O${OPT_LEVEL} ${OPT_STRIP_%STRIP_MODE%} ' +
                '-inline-threshold=${OPT_INLINE_THRESHOLD}',
   'OPT_INLINE_THRESHOLD': '100',
   'OPT_LEVEL': '0',
   'OPT_STRIP_none': '',
   'OPT_STRIP_all': '-disable-opt --strip',
   'OPT_STRIP_debug': '-disable-opt --strip-debug',
 
   # Sandboxed LD is always BFD.
   'LD'          : '${SANDBOXED ? ${LD_SB} ${LD_BFD_FLAGS} ' +
                              ' : ${LD_%WHICH_LD%} ${LD_%WHICH_LD%_FLAGS}}',
 
   'LD_BFD_FLAGS': '-m ${LD_EMUL} ${#LD_SCRIPT ? -T ${LD_SCRIPT}}',
 
   'LD_GOLD_FLAGS': '--native-client --oformat ${LD_GOLD_OFORMAT} ' +
                    '${#LD_SCRIPT ? -T ${LD_SCRIPT} : -Ttext=0x20000}',
 
   'GOLD_PLUGIN_ARGS': '-plugin=${GOLD_PLUGIN_SO} ' +
-                      '-plugin-opt=emit-llvm ' +
-                      '${LIBMODE_NEWLIB && !BAREBONES_LINK ? ' +
-                      '-plugin-opt=-add-nacl-read-tp-dependency ' +
-                      '-plugin-opt=-add-libgcc-dependencies}',
+                      '-plugin-opt=emit-llvm',
 
    # Symbols to wrap
   'WRAP_SYMBOLS': '',
 
   # Common to both GOLD and BFD.
   'LD_FLAGS'       : '-nostdlib ${@AddPrefix:-L:SEARCH_DIRS} ' +
                      '${SHARED ? -shared} ${STATIC ? -static} ' +
                      '${RELOCATABLE ? -relocatable} ' +
                      '${LIBMODE_GLIBC && ' +
                      '!STATIC ? ${@AddPrefix:-rpath-link=:SEARCH_DIRS}}',
@@ skipping 69 matching lines @@
   ( '--pnacl-add-libdep=(.+)', "env.append('LIBDEPS', $0)"),
   ( ('--add-translate-option=(.+)'),
                        "env.append('PNACL_TRANSLATE_FLAGS', $0)"),
   # todo(dschuff): get rid of this when we get closer to tip and fix bug 1941
   ( ('--add-opt-option=(.+)'),
                        "env.append('OPT_FLAGS', $0)"),
 
   ( '-o(.+)',          "env.set('OUTPUT', pathtools.normalize($0))"),
   ( ('-o', '(.+)'),    "env.set('OUTPUT', pathtools.normalize($0))"),
 
-  ( '-barebones-link',       "env.set('BAREBONES_LINK', '1')"),
-
   ( '-shared',         "env.set('SHARED', '1')"),
 
   ( '-static',         "env.set('STATIC', '1')\n"
                        "env.set('SHARED', '0')"),
   ( '-nostdlib',       "env.set('STDLIB', '0')"),
 
   ( '-r',                  "env.set('RELOCATABLE', '1')"),
   ( '-relocatable',        "env.set('RELOCATABLE', '1')"),
 
   ( ('-L', '(.+)'),
@@ skipping 72 matching lines @@
 ]
 
 
 def main(argv):
   ParseArgs(argv, LDPatterns)
 
   if env.getbool('RELOCATABLE'):
     if env.getbool('SHARED'):
       Log.Fatal("-r and -shared may not be used together")
     env.set('STATIC', '0')
-    env.set('BAREBONES_LINK', '1')
 
   if env.getbool('LIBMODE_NEWLIB'):
     if env.getbool('SHARED'):
       Log.Fatal("Cannot generate shared objects with newlib-based toolchain")
     env.set('STATIC', '1')
 
   inputs = env.get('INPUTS')
   output = env.getone('OUTPUT')
 
   if output == '':
@@ skipping 600 matching lines @@
     if IsFlag(f):
       continue
     else:
       if not pathtools.exists(f):
         Log.Fatal("Unable to open '%s'", pathtools.touser(f))
       ret.append(f)
   return ret
 
 if __name__ == "__main__":
   DriverMain(main)