Changes

x86-64: Implement an enhancement for char array System.arraycopy

The setup to run `rep movsd` is not efficient on copying smaller sizes.
The enhancement inlines copy size equal or less than 64 bytes without
using `rep movsd`.

Signed-off-by: Annabelle Huo <Annabelle.Huo@ibm.com>
 (commit: 5eb9e92)

x86-64: Implement an enhancement for byte array System.arraycopy

The setup to run `rep movsb` is not efficient on copying smaller sizes.
The enhancement inlines copy size equal or less than 64 bytes without
using `rep movsb`.

Co-Authored-By: Henry Zongaro <zongaro@ca.ibm.com>
Signed-off-by: Annabelle Huo <Annabelle.Huo@ibm.com>
 (commit: ff6e4cd)

Add JIT options that disable array copy enhancement

`disableArrayCopyByteArrayInlineSmallSizeWithoutREPMOVS`
- Disable array copy enhancement for 8 bit primitive array

`disableArrayCopyCharArrayInlineSmallSizeWithoutREPMOVS`
- Disable array copy enhancement for 16 bit primitive array

Signed-off-by: Annabelle Huo <Annabelle.Huo@ibm.com>
 (commit: a81d5c0)