RFR: 8252684: Move the AArch64 assember test under test/hotspot/gtest [v2]

[Nick Gasson]

> There was a question on the SVE review thread on build-dev [1] a few
> months ago about why there is a Python script and test code under
> src/hotspot/cpu/aarch64. The script generates code to check the
> Assembler instruction encodings against those of the system assembler.
> The test runs every time the debug VM is started.
> 
> AFAIK there's no precedent in the rest of Hotspot for having functional
> tests that run on startup, and we have the existing gtest framework for
> testing internal C++ modules. This patch (perhaps more of an RFC) moves
> the assembler test under test/hotspot/gtest/aarch64.
> 
> The test will now run in tier1, including for release builds. The
> downside is that debug builds won't catch assembler encoding errors
> immediately on startup.
> 
> Tested by injecting an error in one of the instruction encodings and
> verifying `make test TEST="gtest"` fails.
> 
> [1] https://mail.openjdk.java.net/pipermail/build-dev/2020-August/028048.html

Nick Gasson has updated the pull request incrementally with one additional commit since the last revision:

  Move the asmtest output into a separate file

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1476/files
  - new: https://git.openjdk.java.net/jdk/pull/1476/files/d7330dcb..f0604b61

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1476&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1476&range=00-01

  Stats: 1208 lines in 2 files changed: 1 ins; 1205 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1476.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1476/head:pull/1476

PR: https://git.openjdk.java.net/jdk/pull/1476