RFR: 8279560: AArch64: generate_compare_long_string_same_encoding and LARGE_LOOP_PREFETCH alignment [v2]

[Wang Huang]

> Fix on code shape :
> ```c++
>       __ bind(LARGE_LOOP_PREFETCH);
>         __ prfm(Address(str1, SoftwarePrefetchHintDistance));
>         __ prfm(Address(str2, SoftwarePrefetchHintDistance));
> 
>         __ align(OptoLoopAlignment);
> 
> ->
> 
> ```c++
>       __ align(OptoLoopAlignment);
>       __ bind(LARGE_LOOP_PREFETCH);
>         __ prfm(Address(str1, SoftwarePrefetchHintDistance));
>         __ prfm(Address(str2, SoftwarePrefetchHintDistance));
> ``` 
> Thanks to @shipilev  for your great advice. Any comments and suggestions will be appreciated.

Wang Huang has updated the pull request incrementally with one additional commit since the last revision:

  fix copyright years

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7007/files
  - new: https://git.openjdk.java.net/jdk/pull/7007/files/8525d14f..e2873525

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7007&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7007&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7007.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7007/head:pull/7007

PR: https://git.openjdk.java.net/jdk/pull/7007