Add nacl_sdk gyp meta-target.

build/all.gyp

 {
   'includes': [
     'common.gypi',
   ],
   'targets': [
     {
       'target_name': 'pull_in_all',
       'type': 'none',
       'dependencies': [
         '../src/shared/gio/gio.gyp:*',
         '../src/shared/imc/imc.gyp:*',
         '../src/shared/platform/platform.gyp:*',
         '../src/shared/srpc/srpc.gyp:*',
         '../src/shared/utils/utils.gyp:*',
         '../src/trusted/debug_stub/debug_stub.gyp:*',
         '../src/trusted/desc/desc.gyp:*',
         '../src/trusted/nacl_base/nacl_base.gyp:*',
         '../src/trusted/nonnacl_util/nonnacl_util.gyp:*',
         '../src/trusted/perf_counter/perf_counter.gyp:*',
         '../src/trusted/platform_qualify/platform_qualify.gyp:*',
         '../src/trusted/sel_universal/sel_universal.gyp:*',
         '../src/trusted/service_runtime/service_runtime.gyp:*',
         '../src/untrusted/irt/irt.gyp:irt_core_nexe',
         '../src/untrusted/irt_stub/irt_stub.gyp:*',
         '../src/untrusted/nacl/nacl.gyp:*',
         '../src/untrusted/nosys/nosys.gyp:*',
         '../src/untrusted/pthread/pthread.gyp:*',
         '../tests/sel_main_chrome/sel_main_chrome.gyp:*',
+        'nacl_core_sdk.gyp:*',
       ],
       'conditions': [
         # No tests on ARM yet.
         ['target_arch!="arm"', {
           'dependencies': [
             '../tests.gyp:*',
           ],
         }],
         ['target_arch=="arm"', {
           'dependencies': [
             '../src/trusted/validator_arm/validator_arm.gyp:*',
           ],
         }, {
           'dependencies': [
             '../src/trusted/validator_x86/validator_x86.gyp:*',
           ],
         }],
       ],
     },
   ],
 }