Replace dart_core.js with actual compiled SDK

test/test.sh

 #!/bin/bash
 set -e # bail on error
 
 function fail {
   echo -e "Some tests failed"
   return 1
 }
 
 # Arguments passed to the diff tool. We exclude:
 #  - *.map files so they aren't compared, as the diff is not human readable.
@@ skipping 15 matching lines @@
 
 # the directory of this script
 TEST_DIR=$( cd $( dirname "${BASH_SOURCE[0]}" ) && pwd )
 
 # Some tests require being run from the package root
 cd $TEST_DIR/..
 
 # Check minimum SDK version
 ./tool/sdk_version_check.dart 1.9.0-dev.4.0 || fail
 
+./tool/build_sdk.sh
+
 # Remove packages symlinks, and old codegen output
 find test/codegen -name packages -exec rm {} \;
 rm -r test/codegen/actual 2> /dev/null || true
 find test/dart_codegen -name packages -exec rm {} \;
 rm -r test/dart_codegen/actual 2> /dev/null || true
 dart -c test/all_tests.dart || fail
 
 # validate codegen_test output
 pushd test/codegen/ &> /dev/null
 rm -r actual/dev_compiler/ actual/server_mode/dev_compiler/ \
@@ skipping 30 matching lines @@
 #   * local files that have never been added to git,
 #   * subdirectories of test/ and tool/, unless explicitly added. Those dirs
 #     contain a lot of generated or external source we should not reformat.
 (files=`git ls-files 'bin/*.dart' 'lib/*.dart' test/*.dart test/checker/*.dart \
   tool/*.dart | grep -v lib/src/js/`; git status -s $files | grep -q . \
   && echo "Did not run the formatter, please commit edited files first." \
   || (echo "Running dart formatter" ; pub run dart_style:format -w $files))
 popd &> /dev/null
 
 echo -e "All tests pass"