Show calls from the host into the EVM. Shows the call, `evmc_message` fields,
and `evmc_result` fields when the call returns.
(When `show_tx_calls` is manually set to true.)
Signed-off-by: Jamie Lokier <jamie@shareable.org>
New pragma `{.show.}` on a proc definition turns on tracing for that proc.
Every call to it shows the name, arguments and results, if `show_tx_calls` is
manually set to true. This is to trace calls from EVM to host.
This started as a template which took a block expression, but the closure it
used led to illegal capture errors. It was easier to write a macro.
Signed-off-by: Jamie Lokier <jamie@shareable.org>