Experimental scanner: add test file for string / identifier escapes.

test/lexer/cornercases/strings-and-identifiers-with-escapes.js

Index: test/lexer/cornercases/strings-and-identifiers-with-escapes.js
diff --git a/test/lexer/utf-1.js b/test/lexer/cornercases/strings-and-identifiers-with-escapes.js
similarity index 92%
copy from test/lexer/utf-1.js
copy to test/lexer/cornercases/strings-and-identifiers-with-escapes.js
index 2f1ef5209649d4c955c9e0478fd95036e529719c..dac6bf705140959ea3dd0747cf41d9f6c884a143 100644
--- a/test/lexer/utf-1.js
+++ b/test/lexer/cornercases/strings-and-identifiers-with-escapes.js
@@ -25,7 +25,9 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// This file is in utf-8 (or rather, ASCII), but doesn't contain any weird
-// characters.
+"this is a normal string"
+"this is a string with an \xaa escape"
+"this \u00ab too"
+"and \n this\t"
 
-var foobar = 16;
+identifierwith\u26aaescape