RFR: Lower case verify calls

[Coleen Phillimore]

This is another cosmetic change to fix the verify functions so that there is one less null string assert.

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

Commit messages:
 - Lower case verify calls

Changes: https://git.openjdk.java.net/loom/pull/122/files
 Webrev: https://webrevs.openjdk.java.net/?repo=loom&pr=122&range=00
  Stats: 30 lines in 2 files changed: 5 ins; 5 del; 20 mod
  Patch: https://git.openjdk.java.net/loom/pull/122.diff
  Fetch: git fetch https://git.openjdk.java.net/loom pull/122/head:pull/122

PR: https://git.openjdk.java.net/loom/pull/122