Add test for T7878
Add a test for shutting down a process with in-calls in progress
unbreak tests (removal of block/unblock)
Tidy up the driver slightly
Fix library way detection; fixes the ImpSafeOnly* tests when BINDIST=YES

We were checking paths with
    if [ -f '"/path/to/Prelude"' ]
i.e. the " quotes were being quoted by the ' quotes. Now we just
use " quotes (which come from the ghc-pkg output).
Add a test for #7373
Change how we detect what library ways are available

We used to use the base package to do the detection. However, base has
    extra-lib-dirs: @ICONV_LIB_DIRS@
in base.buildinfo.in, which means that if ICONV_LIB_DIRS is set then
the package config will have
    library-dirs: [...]base/dist-install/build /path/for/iconv
and, as paths may be double quoted and contains spaces, this makes it
a little tricky to extra the path that we want to look in (the first
path).

We therefore now use the ghc-prim package, which has no such complication.
Test Trac #7910
Update test now that undefined has an OpenKind forall
Wibbles to error messages
Better error message
Test Trac #7268
Test Trac #7888
Test Trac #7892
Update test for application of (->) to Int#
Improved compiler performance!  Reason unknown, but hey, it's good news
Test Trac #7891 and #7903
Wibble to simplifier output
Test Trac #7906
Make the test actually test the bug!

(Thanks to Martijn for correcting this oversight.)