[aarch64-port-dev ] RFR(M): 8242482: AArch64: Change parameter names of reduction operations to make code clear

[Yang Zhang]

Hi,

Could you please help to review this patch?

JBS: https://bugs.openjdk.java.net/browse/JDK-8242482
Webrev: http://cr.openjdk.java.net/~yzhang/8242482/webrev.00/

This patch is a followup patch of previous discussion.
https://mail.openjdk.java.net/pipermail/aarch64-port-dev/2020-April/008740.html

To make the intent clear, the scalar parameter name is changed to isrc, fsrc or dsrc based on
its data type. The vector parameter name is changed to vsrc. And so does temp register.

Testing: tier1

Regards
Yang