[11u] RFR: 8249672: Include microcode revision in features_string on x86

[Lindenmaier, Goetz]

Hi

I am downporting this for parity with 11.0.10-oracle.

The format string in vm_version_x86 if formatted differently in 11,
so I had to resolve.
I copied some of the line breaks from the source, it really makes
The code more readable.

http://cr.openjdk.java.net/~goetz/wr20/8249672-x86_microcode_vers-jdk11/01/

Please review.

https://bugs.openjdk.java.net/browse/JDK-8249672
https://hg.openjdk.java.net/jdk/jdk/rev/931c949e05e4

Best regards,
  Goetz.