[vector-unstable] Resolve manual merge conflicts on assembler-aarch64.cpp

[Ningsheng Jian]

Hi,

Please help to review:

Webrev: 
http://cr.openjdk.java.net/~njian/vectorapi/asmtest-merge-fix/webrev/

Sandhya helped to do a manual merge of vector-unstable branch with 
default yesterday. This patch adds the missing changes back by resolving 
the conflicts in aarch64-asmtest.py and regenerate code for 
assembler_aarch64.cpp. I also did some minor updates of 
aarch64-asmtest.py to make it not to reformat the generated code, to get 
less diff compared to jdk/jdk.

Thanks,
Ningsheng