[foreign-memaccess+abi] RFR: Fix duplicate declaration in methodData.cpp

[Maurizio Cimadamore]

A recent automatic merge ended up creating a duplicate declaration of a function in methodData.cpp. This patch fixes that. Thanks to Ty for the fix.

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

Commit messages:
 - Fix build issue

Changes: https://git.openjdk.java.net/panama-foreign/pull/428/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=428&range=00
  Stats: 12 lines in 1 file changed: 0 ins; 12 del; 0 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/428.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/428/head:pull/428

PR: https://git.openjdk.java.net/panama-foreign/pull/428