Some tests had previously been passing despite actually causing a crash, due
to the required output being too loosely specified. This ensures the bare minimum:
that every test has an expected EXIT code and SIGNAL result.
The codes suggested were taken from the test's current output, and only applied for
CORE tests, but hand inspection suggests these choices are reasonable.
Added a new option "-p" to test.pl to request printing failure logs instead of
doing so via an external script. This simplifies various Makefiles and enables
use in cmake builds.
Made the first step of the chain.sh remove the generated .gb file from
previous runs. This ensures that if the goto-cc step fails, misleading
results are not generated.
Chris Smowton