[foreign-memaccess+abi] RFR: 8277845: Clean up use if ProgrammableInvoker/UpcallHandler.USE_INTRINSICS in tests.

[Jorn Vernee]

This PR cleans up use of USE_INTRINSICS flags in the tests, which was removed a while ago.

I also noticed that TestMatrix.java didn't have a copyright header, so I've added one. (the diff looks a little mangled as a result). It also wasn't setting the UPCALL_TEST_TYPE flag when running TestUpcall, so I've added that flag.

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Commit messages:
 - Remove uses of USE_INTRINSICS

Changes: https://git.openjdk.java.net/panama-foreign/pull/629/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=629&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277845
  Stats: 335 lines in 4 files changed: 10 ins; 266 del; 59 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/629.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/629/head:pull/629

PR: https://git.openjdk.java.net/panama-foreign/pull/629