RFR: 8276472: align_metadata_size is a nop

[Coleen Phillimore]

I just added a comment to this and took out the align_up call.  I like align_metadata_size where it is and changing to WordSize doesn't add more safety imo.  Also found unused function while looking for units of metadata size.
Tested with tier1 on Oracle supported platforms.

-------------

Commit messages:
 - 8276472: align_metadata_size is a nop

Changes: https://git.openjdk.java.net/jdk/pull/7150/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7150&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8276472
  Stats: 8 lines in 2 files changed: 1 ins; 3 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7150.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7150/head:pull/7150

PR: https://git.openjdk.java.net/jdk/pull/7150