Add default constraint_settings and values in new package @bazel_tools//platforms. 

Part of #2219.

--
Change-Id: I312c70e0c9064cbf4c4346a59bff04ada92e4890
Reviewed-on: https://cr.bazel.build/9412
PiperOrigin-RevId: 151016060
MOS_MIGRATED_REVID=151016060
diff --git a/src/create_embedded_tools.sh b/src/create_embedded_tools.sh
index a883d95..4ad0177 100755
--- a/src/create_embedded_tools.sh
+++ b/src/create_embedded_tools.sh
@@ -42,6 +42,7 @@
 
   case "$i" in
     *tools/jdk/BUILD*) OUTPUT_PATH=tools/jdk/BUILD ;;
+    *tools/platforms/platforms.BUILD) OUTPUT_PATH=platforms/BUILD ;;
     *JavaBuilder*_deploy.jar) OUTPUT_PATH=tools/jdk/JavaBuilder_deploy.jar ;;
     *JacocoCoverage*_deploy.jar) OUTPUT_PATH=tools/jdk/JacocoCoverage_deploy.jar ;;
     *turbine_deploy.jar) OUTPUT_PATH=tools/jdk/turbine_deploy.jar ;;