RFR: 8277619: AArch64: Incorrect parameter type in Advanced SIMD Copy assembler functions

[Fei Gao]

Mov (from general), incorrectly uses SIMD_Arrangement as the parameter
type of the assembler function. However, from Arm ARM [1], it's more
precise to use SIMD_RegVariant here.

The situation is similar to Mov(to general) [2].

Note that as Mov(to general) is an alias of UMOV, we turn to re-use
UMOV encoding for Mov(to general) in this patch.

[1] https://developer.arm.com/documentation/ddi0602/2020-12/SIMD-FP-Instructions/MOV--from-general---Move-general-purpose-register-to-a-vector-element--an-alias-of-INS--general--
[2] https://developer.arm.com/documentation/ddi0602/2020-12/SIMD-FP-Instructions/MOV--to-general---Move-vector-element-to-general-purpose-register--an-alias-of-UMOV-

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Commit messages:
 - 8277619: AArch64: Incorrect parameter type in Advanced SIMD Copy assembler functions

Changes: https://git.openjdk.java.net/jdk/pull/6629/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6629&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277619
  Stats: 52 lines in 7 files changed: 1 ins; 3 del; 48 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6629.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6629/head:pull/6629

PR: https://git.openjdk.java.net/jdk/pull/6629