Add support for capturing RTS statistics from compilation

This adds a simple mechanism for capture runtime system statistics from compiler invocations. It's pretty crude, but should nevertheless be useful.

ci/TestPatches.hs

@@ -254,9 +254,10 @@ buildPackage cfg pname version = do
     (makeTestCabalFile cfg pname version)
 
   -- run the build
+  absDirName <- makeAbsolute "./store"
   code <- runProcess $ setWorkingDir dirName
                      $ proc "cabal"
-                     $ ["new-build"] ++ cabalOptions cfg
+                     $ ["--store-dir="++absDirName, "v2-build"] ++ cabalOptions cfg
 
   -- figure out what happened
   let planPath = dirName </> "dist-newstyle" </> "cache" </> "plan.json"
@@ -383,7 +384,7 @@ setup cfg = do
     , MakeConstraints.allowNewer MakeConstraints.bootPkgs
     ] ++ map PP.text extraFragments
 
-  runProcess_ $ proc "cabal" ["new-update"]
+  runProcess_ $ proc "cabal" ["v2-update"]
 
   -- Force cabal to rebuild the index cache.
   buildPackage cfg "acme-box" (mkVersion [0,0,0,0])