This adds a new feature experimental_x64 for CLIF tests.
A test is run in the new x64 backend iff:
- either the test doesn't have an x86_64 target requirement, signaling
it must be target agnostic or not run on this target.
- or the test does require the x86_64 target, and the test is marked
with the `experimental_x64` feature.
This required one workaround in the parser. The reason is that the
parser will try to use information not provided by the TargetIsa adapter
for the Mach backends, like register names. In particular, parsing test
may fail before the test runner realizes that the test must not be run.
In this case, we early return an almost-empty TestFile from the parser,
under the same conditions as above, so that the caller may filter out
the test properly.
This also copies two tests from the test suite using the new backend,
for demonstration purposes.
* All: Drop 'basic-blocks' feature
This makes it so that 'basic-blocks' cannot be disabled and we can
start assuming it everywhere.
* Tests: Replace non-bb filetests with bb version
* Tests: Adapt solver-fixedconflict filetests to use basic blocks
Cranelift can be compiled with feature flags which can change its output. To
accomodate changes of output related to feature flags, test file can now include
`feature "..."` and `feature ! "..."` directives in the preamble of the test
file.
The test runner would skip the test if the flag does not match the expectation
of the test case.
* Add options for parsing test files
This change allows adding parsing parameters more easily; e.g. a parameter is needed for setting the default calling convention for functions parsed as a part of the `run` test feature.
* Set default calling convention that of the host for `test run` file tests
Previously `test run` used the parser's hard-coded CallConv::Fast as the default calling convention but with this change any test being `run` will use the default calling convention of the machine running the test. `test run` will now throw an error if the calling convention of the function does not match the host's.
