[jdk11u-dev] RFR: 8210385: Clean up JNI_ENV_ARG and factorize the macros for vmTestbase/jvmti[A-N] tests

[Goetz Lindenmaier]

I backport this for parity with 11.0.14-oracle.

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Commit messages:
 - Backport fe326ad022a67e2539df2121f8f074d26b0b4cce

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/655/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=655&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8210385
  Stats: 1012 lines in 46 files changed: 0 ins; 822 del; 190 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/655.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/655/head:pull/655

PR: https://git.openjdk.java.net/jdk11u-dev/pull/655