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

pnacl/driver/pnacl-driver.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 98 matching lines @@
   'PREFIXES'         : '', # Prefixes specified by using the -B flag.
 
   # Library Strings
   'EMITMODE'         : '${STATIC ? static : ${SHARED ? shared : dynamic}}',
 
   'LD_ARGS' : '${STDLIB ? ${LD_ARGS_%LIBMODE%_%EMITMODE%}' +
                       ' : ${LD_ARGS_nostdlib}}',
 
   # ${ld_inputs} signifies where to place the objects and libraries
   # provided on the command-line.
-  'LD_ARGS_nostdlib': '-barebones-link -nostdlib ${ld_inputs}',
+  'LD_ARGS_nostdlib': '-nostdlib ${ld_inputs}',
 
   'LD_ARGS_newlib_static':
     '-l:crt1.o -l:nacl_startup.bc ${ld_inputs} ' +
     '--start-group -lgcc_eh -lgcc -lc -lnacl ' +
     '${LIBSTDCPP} -l:libcrt_platform.a --end-group',
 
   # The next three are copied verbatim from nacl-gcc
   'LD_ARGS_glibc_static':
     '-l:crt1.o -l:crti.o -l:crtbeginT.o ' +
     '${ld_inputs} ${LIBSTDCPP} ' +
@@ skipping 411 matching lines @@
     chain.add(RunNativeAS, 'o')
     cur_type = 'o'
   if cur_type == output_type:
     return
 
   Log.Fatal("Unable to compile .%s to .%s", input_type, output_type)
 
 
 if __name__ == "__main__":
   DriverMain(main)