[8u] Request for enhancement backport approval for CR 8176329 - jdeps to detect MR jar file and output a warning

[Brent Christian]

Hi,

I would like to add the following small enhancement to 8u:

"jdeps to detect MR jar file and output a warning"

https://bugs.openjdk.java.net/browse/JDK-8176329

Rationale:
If the 8u version of jdeps encounters a Multi-Release jar, the user 
should be warned that the JDK 9 version of jdeps should be used instead.

The only change is to the jdeps tool itself (no change to the runtime). 
The change is low risk and very localized to check an input JAR file for 
the "Multi-Release" attribute.


Thanks,
-Brent