The impetus for this was mostly that after my Ubuntu upgrade, pylint
suddenly starting to apply python3 rules, and I suppose it's time to
adopt python 3 now that it's been released for more than a decade.

This test checks that an I$ appears to be physically indexed.

* Parse inf/nan floats.

* Enable mstatus.fs in SimpleF18Test

Also accept "unable to fetch" message when FPRs aren't supported.

* Add config files for HiFive Unleashed.

* Add configs to flash HiFive Unleashed.

All tests pass.

The latest OpenOCD doesn't need (nor support) this anymore.

Hopefully this is enough information that I can simply point people who
submit OpenOCD changes to it, and they can run the tests themselves.

Instead of relying on $RISCV.  Using $RISCV was common in the early
days, but nowadays many tools are simply installed alongside the rest of
the system.

* Let the debugger enable mstatus.F if necessary.

* Ignore (some) gdb debug output.

* Increase timeout.

* Make newer version of pylint happy.

* Let the debugger enable mstatus.F if necessary.

* Ignore (some) gdb debug output.

* Increase timeout.

* Make newer version of pylint happy.

* Parse floats the way mainline gdb prints them.

For 64-bit floats, it shows both float and double results. Now more
tests pass using mainline gdb.

* Disable ANSI when talking to gdb.

Helps more tests pass with mainline gdb.

* Parse {float=...,double=...} in "info registers"

Makes tests work better with mainline gdb.

Also work with the new command line options that were renamed in
https://github.com/riscv/riscv-isa-sim/pull/299

Passes on spike and Arty. Won't merge until
https://github.com/riscv/riscv-openocd/pull/364 merges.

This test confirms that in SMP configurations OpenOCD halts the harts
near-simulatenously. (It'll also check for resume, but that's not
implemented yet so commented out for now.)

* WIP

* Use hwthread everywhere.

* Test `-rtos hwthread`.

Also tweak timeouts a bit so that we don't have ridiculous timeouts for
simple operations.

* Tweak timeouts so tests pass on a loaded system.

Add testing of run-test/idle cases.

Fix MemTestBlock

This test used to false pass on 64-bit targets because gdb doesn't like
using Intel hex files on 64-bit targets.

Increase some timeouts in case memory access is slow.

Use more than 1KB for download test.

This is a pretty old bug. I limited the size to 256KB because against
spike my machine gets about 8KB/s, and I don't want to wait forever for
`make` to pass.

Tweak debug tests to run out of flash.

Added MemTestBlockReadInvalid verifying the corresponding OpenOCD fix