Migrate more tests from blink repository.

test/webkit/fast/js/exception-registerfile-shrink.js

Index: test/webkit/fast/js/exception-registerfile-shrink.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/fast/js/exception-registerfile-shrink.js
similarity index 83%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/fast/js/exception-registerfile-shrink.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..d534db3c3dc28e43c109b2053a331bc23c15218a 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/fast/js/exception-registerfile-shrink.js
@@ -22,10 +22,10 @@
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 description(
-"Tests the behavior of Array.prototype.concat while the array is having a bad time due to one of the elements we are concatenating."
+"Test for <a href='https://bugs.webkit.org/show_bug.cgi?id=41948'>REGRESSION(r60392): Registerfile can be unwound too far following an exception</a>. If the test doesn't crash, you pass."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
-
+eval('try { throw 0; } catch(e) {}');
 
+var x = new String();
+'' + escape(x.substring(0, 1));