[vectorIntrinsics] RFR: 8244490: [vector] Move Vector API micro benchmarks under test/micro

[Marcus G K Williams]

Vector API micro benchmarks are currently located under test/jdk/jdk/incubator/vector/benchmark which makes them rather as "dead" code without possibility to built and run.

The proper location for micro benchmarks is actually test/micro/ directory.
It would be nice to move Vector API benchmarks there so they can be built automatically as part 'test-image' make target.
Once they are built they can be run as
 make run-test TEST=micro:BENCHMARK_TEST_NAME

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

Commit messages:
 - add missing readme pom.xml
 - Vector Micro Tests Draft Move

Changes: https://git.openjdk.java.net/panama-vector/pull/77/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=77&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8244490
  Stats: 461 lines in 97 files changed: 281 ins; 128 del; 52 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/77.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/77/head:pull/77

PR: https://git.openjdk.java.net/panama-vector/pull/77