tools/ccanlint: build tests are now compulsory Offer to run debugger when test fails, with breakpoint.
Now we compile everything into the tmp dir.
ccanlint: compile and run tests. This means we should skip building if there are no C files in module: running tests requires building the module, but not necessarily that it has any C files.
Build tests for ccan. More sophisticated skipping: skip dependencies when one fails as well. Allow tests to change their total_score; only access it after running (other than to check it's non-zero).