Individual compilation passes call the corresponding timing::*()
function and hold on to their timing token while they run. This causes
nested per-pass timing information to be recorded in thread-local
storage.
The --time-passes command line option prints a pass timing report to
stdout.
Add a settings::FlagsOrIsa struct which represents a flags reference and
optionally the ISA it belongs to. Use this for passing flags/isa
information to the verifier.
The verify_function() and verify_context() functions are now generic so
they accept either a &Flags or a &TargetISa argument.
Fix the return_at_end verifier tests which no longer require an ISA
specified. The signle "set return_at_end" flag setting now makes it to
the verifier even when no ISA is present to carry it.
When the CRETONNE_DBG environment variable is set, send debug messages
to a file named cretonne.dbg.*.
The trace facility is only enabled when debug assertions are on.
Add a Function::display() method which can include ISA-specific
information when printing the function.
If a test file has a unique ISA, use that in the `test cat`
implementation.
Include the test file preamble comments when building a filecheck
instance for every function in the file.
This makes it possible to define common regex variables in the preamble
and use these definitions for all the functions.
