Remove some unused references to the pnacl-nativeld tool

pnacl-nativeld was only used directly by service_runtime/nacl.scons, and
this use has been disabled for a while.

This will help us to remove pnacl-nativeld as a public entry point,
which will aid further cleanups.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3873
TEST=trybots
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/329793004

git-svn-id: svn://svn.chromium.org/native_client/trunk/src/native_client/site_scons@13340 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2
diff --git a/site_tools/naclsdk.py b/site_tools/naclsdk.py
index 3b3df17..4279b95 100755
--- a/site_tools/naclsdk.py
+++ b/site_tools/naclsdk.py
@@ -198,7 +198,6 @@
   pnacl_cxx = binprefix + 'clang++' + binext
 
   pnacl_ld = binprefix + 'ld' + binext
-  pnacl_nativeld = binprefix + 'nativeld' + binext
   pnacl_disass = binprefix + 'dis' + binext
   pnacl_finalize = binprefix + 'finalize' + binext
   pnacl_strip = binprefix + 'strip' + binext
@@ -252,7 +251,6 @@
               # with shared libraries except use them with the toolchain.
               SHLINK=pnacl_cxx + ld_arch_flag + pnacl_ld_flags,
               LD=pnacl_ld,
-              NATIVELD=pnacl_nativeld,
               AR=pnacl_ar,
               AS=pnacl_as + ld_arch_flag,
               RANLIB=pnacl_ranlib,
@@ -288,7 +286,7 @@
              CXX=arch_flag + cc_flags,
              ASPP=arch_flag + cc_flags,
              LINK=cc_flags) # Already has -arch
-  env['LD'] = '${NATIVELD}' + arch_flag
+  env['LD'] = 'NO-NATIVE-LD-INVOCATION-ALLOWED'
   env['SHLINK'] = '${LINK}'
   if env.Bit('built_elsewhere'):
     _StubOutEnvToolsForBuiltElsewhere(env)