[foreign-memaccess+abi] RFR: Split tests [v3]

[Per Minborg]

> This PR suggests splitting up a test class into two and only run the slow one on 64-bit systems.

Per Minborg has updated the pull request incrementally with one additional commit since the last revision:

  Reformat copyright header

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

Changes:
  - all: https://git.openjdk.org/panama-foreign/pull/908/files
  - new: https://git.openjdk.org/panama-foreign/pull/908/files/2ac225c9..23394170

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=panama-foreign&pr=908&range=02
 - incr: https://webrevs.openjdk.org/?repo=panama-foreign&pr=908&range=01-02

  Stats: 19 lines in 1 file changed: 3 ins; 4 del; 12 mod
  Patch: https://git.openjdk.org/panama-foreign/pull/908.diff
  Fetch: git fetch https://git.openjdk.org/panama-foreign.git pull/908/head:pull/908

PR: https://git.openjdk.org/panama-foreign/pull/908