RFR: 8344393: RISC-V: Remove option UseRVVForBigIntegerShiftIntrinsics

[Fei Yang]

Seem that it's more reasonable to control BigInteger shift intrinsics with`UseRVV` option.
I witnessed performance benefit on BPI-F3 with the RISC-V vector extension. And it's still
possible to disable these two intrinsics with `-XX:DisableIntrinsic` option.

JMH on BPI-F3 (has vector 1.0) for reference:

Without instrinsic:
BigIntegers.testLeftShift                        N/A  avgt   15      4083.865 ±   224.139  ns/op
BigIntegers.testRightShift                       N/A  avgt   15      1745.833 ±    44.855  ns/op

With instrinsic:
BigIntegers.testLeftShift                        N/A  avgt   15      2243.095 ±    24.821  ns/op
BigIntegers.testRightShift                       N/A  avgt   15      1558.770 ±    36.191  ns/op

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Commit messages:
 - 8344393: RISC-V: Remove option UseRVVForBigIntegerShiftIntrinsics

Changes: https://git.openjdk.org/jdk/pull/22202/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22202&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344393
  Stats: 4 lines in 3 files changed: 0 ins; 3 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22202.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22202/head:pull/22202

PR: https://git.openjdk.org/jdk/pull/22202