RFR: [type-classes] 8377123: Add SIZE and BYTES static fields to UnsignedInt

[Joe Darcy]

Add SIZE and BYTES fields to UnsignedInt, analagous to those fields from java.lang.Integer.

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Commit messages:
 - 8377123: Add SIZE and BYTES static fields to UnsignedInt

Changes: https://git.openjdk.org/valhalla/pull/2028/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2028&range=00
  Stats: 12 lines in 1 file changed: 0 ins; 1 del; 11 mod
  Patch: https://git.openjdk.org/valhalla/pull/2028.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2028/head:pull/2028

PR: https://git.openjdk.org/valhalla/pull/2028