RFR: 8352730: RISC-V: Disable tests in qemu-user [v3]

[Robbin Ehn]

> Hi, for you to consider.
> 
> These tests constantly fails in qemu-user.
> Either the require host to be same arch or they are very very slow in emulation.
> E.g. "ptrace(PTRACE_ATTACH, ..) failed for 405157: Function not implemented'" for SA tests.
> This is the initial set of tests, there are many more, but I need to do some more verification for those.
> 
> From bug:
>> qemu-user/rv64 sets uarch to "qemu" in /proc/cpuinfo (qemu-system do not do that).
>> We add this uarch to CPU feature string.
>> This means we can use jtreg 'require' with cpu string to filter out tests in qemu-user.
> 
> Relevant qemu code:
> https://github.com/qemu/qemu/blob/170825d14d88a1ce7fae98d5a928480f2f329b22/linux-user/riscv/target_proc.h#L29
> 
> Relevant hotspot code:
> https://github.com/openjdk/jdk/blob/fa0b18bfde38ee2ffbab33a9eaac547fe8aa3c7c/src/hotspot/os_cpu/linux_riscv/vm_version_linux_riscv.cpp#L250
> 
> Tested that the require only filters out tests in qemu+riscv64.
> 
> Thanks!
> 
> /Robbin

Robbin Ehn has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge branch 'master' into qemu-user-issues
 - Revert
 - Merge branch 'master' into qemu-user-issues
 - Merge branch 'master' into qemu-user-issues
 - more
 - more
 - native or very long

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24229/files
  - new: https://git.openjdk.org/jdk/pull/24229/files/965424ac..73968ab8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24229&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24229&range=01-02

  Stats: 9932 lines in 248 files changed: 5027 ins; 4362 del; 543 mod
  Patch: https://git.openjdk.org/jdk/pull/24229.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24229/head:pull/24229

PR: https://git.openjdk.org/jdk/pull/24229