RFR: 8157834: aarch64: Hello World crashes with fastdebug build

[Edward Nevill]

Hi,

Please review the following webrev

http://cr.openjdk.java.net/~enevill/8157834/webrev/

jira issue: https://bugs.openjdk.java.net/browse/JDK-8157834

This crash is caused by StrIndexOf being called with argument encoding != UU even though CompactStrings is disabled.

Fix is to implement LL, UL and LU encodings for StrIndexOf.

All the best,
Ed.