[vectorIntrinsics+mask] RFR: 8272745: VectorAPI: Vector/Mask type cleanup for masked vector intrinsics [v2]

[Eric Liu]

> Some of the VectorAPIs were inconsistent with their intrinsic
> declarations, and some of the type arguments were not precise enough as
> well. E.g., The return type of "unaryOp" should be a subtype of "Vector"
> instead of an all-purpose "Object" [1][2].
> 
> The imprecise declarations and type arguments would not effect the
> correctness but bring bad readability and make the code hard to
> maintain. This patch is a cleanup for those mismatched declarations of
> VectorAPIs.
> 
> [1] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics%2Bmask/src/java.base/share/classes/jdk/internal/vm/vector/VectorSupport.java#L269
> [2] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics%2Bmask/src/hotspot/share/classfile/vmIntrinsics.hpp#L812

Eric Liu has updated the pull request incrementally with one additional commit since the last revision:

  more thorough cleanup
  
  Change-Id: I22387cb5ae843cbf61104c3e01003d8e89b311a2

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

Changes:
  - all: https://git.openjdk.java.net/panama-vector/pull/117/files
  - new: https://git.openjdk.java.net/panama-vector/pull/117/files/7e0b0e51..82f323a8

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=117&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=117&range=00-01

  Stats: 400 lines in 3 files changed: 208 ins; 13 del; 179 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/117.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/117/head:pull/117

PR: https://git.openjdk.java.net/panama-vector/pull/117