Update to new missing-method-decl warning style

As a side-effect, the new `{-# MINIMAL #-}` facility (see #7633) changes
the existing separate warnings for each missing method declaration:

{{{
No explicit method or default declaration for ‛+’
In the instance declaration for ‛Num T’
}}}

to a single warning per class of the following form:

{{{
No explicit implementation for
  ‛+’, ‛*’, ‛abs’, ‛signum’, and ‛fromInteger’
In the instance declaration for ‛Num T’
}}}

This commit adapts the reference output files in the testsuite to follow
this change in GHC's warnings messages.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Tests for MINIMAL pragma (#7633)
Follow changes in [12a8244/ghc-prim] (#7633)
Follow changes in [7ab62490/base] (re #7633)
Trailing whitespaces
Follow changes in comparison primops (see #6135)
Fix T4007

Accidentally broken by my last commit
Fix performance failures on x86_64
Test driver: Print total time spent at the end
Test driver: Implement different verbosities

Select verbosity with "make VERBOSE=n". Options so far:
 n=0: No per-test output
 n=1: Only failing test results
 n=2: As above, plus progress information (names of all tests)
 n=3: As aobve, plus commands called.
Default currently is n=3, although n=2 might be a nicer default.
Test Trac #8280
Test Trac #8129
test Trac #7800
Test Trac #8333
Typos
T7574 is now passing (#7574)
linker_unload is now passing (#8192)
Wibble after #8218

The new hidden line in output of tcfail181 is

instance Monad m => Monad (Control.Applicative.WrappedMonad m).

It might seem weird that Control.Applicative is suggested when
not imported, but it's almost certainly a side-effect of AMP and
it's harmless.
Driver: Fix % operator typo
Add some tests for type-level subtraction.