RFR: 8253913: unify gtest test names

[Igor Ignatyev]

Hi all,

could you please review this small and trivial patch that unifies the names of hotspot gtests? in some cases, "_test"
is added to gtest names, in others it isn't. given some tests specify "test" in their names, so we get "test_test" like
in `UninitializedDoubleElementWorkerDataArrayTest.sum_test_test_vm`. the patch removes `_test` from the suffixes added
by `TEST*` macros.

testing:
✅ `make test TEST=gtest` on macosx-x64
⏳ `test/hotspot/jtreg/gtest/` on {linux,windows,macosx}-x64

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Commit messages:
 - 8253913: unify gtest test names

Changes: https://git.openjdk.java.net/jdk/pull/475/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=475&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253913
  Stats: 11 lines in 2 files changed: 4 ins; 0 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/475.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/475/head:pull/475

PR: https://git.openjdk.java.net/jdk/pull/475