RFR: 8257137: Revise smov and umov in aarch64 assembler [v2]

[Hao Sun]

> 1. Both smov and umov lack of checking the register type validity.
>    Register type must be 'B', 'H' or 'S' for smov [1].
>    Register type can NOT be 'Q' for umov [2].
>    Such checks are added.
> 
> 2. smov and umov have different explanations on 'Q' field, i.e. bit 30
> of the insturction, but current assembler implementation mixed it up.
>    For umov, 'Q' field can only be set when register type 'D' is given
>    [2]. However, this field of smov must be set for register type 'S'
>    [1], that is, 'Q' field can be optional for register type 'B' or 'H'.
> 
>    Current implementation only took the umov scenario into account. As a
>    result, runtime error ILL_ILLOPN would occur if 'smov(Register,
> 		   FloatRegister, S, index)' is used.
> 
>    We put them into two separate functions and make 'Q' field always set
>    for smov. That means 'SMOVX' (64-bit register variant) is generated
>    for all cases since it's compatible with our current usages of 'SMOVW'.
>    Existing usages of smov have been double checked and this patch does
>    not affect them.
> 
> 3. Smoke tests are also added.
> 
> [1]. https://developer.arm.com/docs/ddi0602/f/simd-and-floating-point-instructions-alphabetic-order/smov-signed-move-vector-element-to-general-purpose-register
> [2]. https://developer.arm.com/docs/ddi0602/f/simd-and-floating-point-instructions-alphabetic-order/umov-unsigned-move-vector-element-to-general-purpose-register
> 
> 
> Note that Jtreg tier1 and jdk::tier3 have been tested and all tests passed without new failures.

Hao Sun has updated the pull request incrementally with one additional commit since the last revision:

  Update the copyright notice to 2021
  
  Update the copyright notice to 2021.
  
  Change-Id: I7fe485e768ccac45a4861cd3c061aedc13fef579
  CustomizedGitHooks: yes

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1586/files
  - new: https://git.openjdk.java.net/jdk/pull/1586/files/a40c0d88..3f84aaa5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1586&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1586&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1586.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1586/head:pull/1586

PR: https://git.openjdk.java.net/jdk/pull/1586