Format IntegrationTests2

Move CPP definitions into a separate module so that Fourmolu can work
its magic.

Author: 9999years

cabal-install/cabal-install.cabal

@@ -392,6 +392,9 @@ test-suite integration-tests2
   hs-source-dirs: tests
   default-language: Haskell2010
 
+  other-modules:
+    IntegrationTests2.CPP
+
   build-depends:
         bytestring,
         cabal-install,