If OpArgIntReg is incorrectly scheduled, that causes it to be spilled
incorrectly, which causes the argument to not be considered live
at the start of the function.
This is the test for CL 462858
Add a brief mention of why CL 462858 is needed in the scheduling code.
Change-Id: Id199456f88d9ee5ca46d7b0353a3c2049709880e
Reviewed-on: https://go-review.googlesource.com/c/go/+/462899 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>