RFR: 8263649: AArch64: update cas.m4 to match current AD file [v3]

[Nick Gasson]

> There's a block of code in aarch64.ad that was generated from cas.m4 and
> is surrounded by:
> 
>   // BEGIN This section of the file is automatically generated. Do not edit --------------
> 
> However this section has been modified several times since it was
> generated and no longer matches the output of the M4 file. This patch
> updates cas.m4 to reflect the current code.

Nick Gasson has updated the pull request incrementally with one additional commit since the last revision:

  Fix comment

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3045/files
  - new: https://git.openjdk.java.net/jdk/pull/3045/files/fb4bbe5f..84271589

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3045&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3045&range=01-02

  Stats: 29 lines in 2 files changed: 1 ins; 0 del; 28 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3045.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3045/head:pull/3045

PR: https://git.openjdk.java.net/jdk/pull/3045