RFR: 8292511: AArch64: Align CPU feature name for NEON with hwcap

[Pengfei Li]

AArch64 hwcap uses `asimd` to represent the CPU feature of NEON. But in
vm_version_aarch64.hpp, this name is redefined as `simd`. This renaming
looks trivial but can easily lead to bugs in test cases as more and more
people start writing jtreg IR tests today.

For example, if someone just finds CPU feature name from some documents
or `/proc/cpuinfo`, and writes below annotations in his test case, the
test case won't run on AArch64.
- `@requires vm.cpu.features ~= ".*asimd.*"`
- `@IR(applyIfCPUFeature = {"asimd", "true"}, counts = {...})`

So in this patch we propose to align the CPU feature names. Some related
jtreg cases are also updated. There's another misalignment of the names
for CPU feature `sha2`. We don't change it as we have some discussions
in https://bugs.openjdk.org/browse/JDK-8285266.

Tested tier1 and hotspot:compiler/vectorapi on x86 and AArch64.

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Commit messages:
 - 8292511: AArch64: Align CPU feature name for NEON with hwcap

Changes: https://git.openjdk.org/jdk/pull/9913/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9913&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292511
  Stats: 17 lines in 5 files changed: 0 ins; 0 del; 17 mod
  Patch: https://git.openjdk.org/jdk/pull/9913.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9913/head:pull/9913

PR: https://git.openjdk.org/jdk/pull/9913