Change the simpleperf update script to use the new branch.

I've removed 32-bit Linux and 32-bit macOS because they're unsupported.
The build server only has the binaries as a side-effect of the ART folks
doing some host-side testing of 32-bit ART.

The Windows situation seems a bit confused: we copy the 32-bit .exe into
the 64-bit directory, but copy the 64-bit .dll. I've left this as it
was, but added a couple of TODO comments.

Bug: http://b/128690014
Test: ./scripts/update.py --bid 5436767 -vv
Change-Id: I1a1429457c27be8900401437234dc9394d5b4b26
1 file changed