RFR Update JarSigning.keystore

[Weijun Wang]

test/jdk/sun/security/tools/jarsigner/JarSigning.keystore is still using 512-bit DSA and it's disabled in jar signing now.

I just updated it and added a README.

diff --git a/test/jdk/sun/security/tools/jarsigner/JarSigning.keystore.README b/test/jdk/sun/security/tools/jarsigner/JarSigning.keystore.README
new file mode 100644
--- /dev/null
+++ b/test/jdk/sun/security/tools/jarsigner/JarSigning.keystore.README
@@ -0,0 +1,5 @@
+#JarSigning.keystore is generated with
+
+rm JarSigning.keystore
+keytool -genkeypair -keystore JarSigning.keystore -storepass bbbbbb -keypass bbbbbb -alias b -dname CN=b -keyalg DSA
+keytool -genkeypair -keystore JarSigning.keystore -storepass bbbbbb -keypass bbbbbb -alias c -dname CN=c -keyalg RSA

bugs.openjdk.java.net is down for maintenance and I will file a bug later.

Running tier1+tier2 now...

Thanks
Max