GHC is too verbose by default (source/object paths)

With the default verbosity, GHC shows the path of the source file and the path of the object file (or "interpreted" in GHCi) making the lines very long as in the following example:

[133 of 159] Compiling ViperVM.Arch.Linux.Internals.Input ( src/lib/ViperVM/Arch/Linux/Internals/Input.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/ViperVM/Arch/Linux/Internals/Input.o )
[134 of 159] Compiling ViperVM.Arch.Linux.Input ( src/lib/ViperVM/Arch/Linux/Input.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/ViperVM/Arch/Linux/Input.o )
[135 of 159] Compiling ViperVM.System.Input ( src/lib/ViperVM/System/Input.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/ViperVM/System/Input.o )
[136 of 159] Compiling ViperVM.Arch.Linux.Internals.Sound ( src/lib/ViperVM/Arch/Linux/Internals/Sound.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/ViperVM/Arch/Linux/Internals/Sound.o )
[137 of 159] Compiling ViperVM.Arch.Linux.Internals.Graphics ( src/lib/ViperVM/Arch/Linux/Internals/Graphics.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/ViperVM/Arch/Linux/Internals/Graphics.o )

In most cases, I think we don't need these paths. I propose that we keep this output for the verbose mode and that we change the default behaviour to something like:

[135 of 159] Compiling ViperVM.System.Input (.hs -> .o)
[136 of 159] Compiling ViperVM.Arch.Linux.Internals.Sound (.hs -> .o)
-- GHCi
[137 of 159] Compiling ViperVM.Arch.Linux.Internals.Graphics (.hs -> interpreted)

It is also particularily nice with BackPack that uses hashes in output paths: we may not want to expose them to users by default. Example:

   [1 of 1] Including p[A=r:A]
     Instantiating p[A=r:A]
-    [1 of 2] Compiling A[sig]           ( p/A.hsig, bkp26.out/p/p-8YQRY0unRYZCev5HBjXieS/A.o )
-    [2 of 2] Compiling P                ( p/P.hs, bkp26.out/p/p-8YQRY0unRYZCev5HBjXieS/P.o )
-  [1 of 1] Compiling M                ( q/M.hs, bkp26.out/q/M.o )
+    [1 of 2] Compiling A[sig]          (.hsig -> .o)
+    [2 of 2] Compiling P               (.hs -> .o)
+  [1 of 1] Compiling M               (.hs -> .o)

Trac metadata

Trac field	Value
Version	8.0.1
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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