Integrated: [type-classes] JDK-8377533: Fix typo in Numerical

[Joe Darcy]

Fix a typo and improve wording.

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Commit messages:
 - JDK-8377533: Fix typo in Numerical

Changes: https://git.openjdk.org/valhalla/pull/2070/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2070&range=00
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/valhalla/pull/2070.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2070/head:pull/2070

PR: https://git.openjdk.org/valhalla/pull/2070