Revert the split into library and executable in cabal file. Hadrian currently...

Revert the split into library and executable in cabal file. Hadrian currently does not support building utils it ships using this configuration.

hpc-bin.cabal

@@ -22,11 +22,13 @@ Flag build-tool-depends
     Description: Use build-tool-depends
     Default: True
 
-library
+executable hpc
     default-language: Haskell2010
-    hs-source-dirs: src
-    exposed-modules: 
-                   HpcParser
+    hs-source-dirs:
+      app,
+      src
+    main-is: Main.hs
+    other-modules: HpcParser
                    HpcCombine
                    HpcDraft
                    HpcFlags
@@ -37,8 +39,7 @@ library
                    HpcShowTix
                    HpcUtils
                    HpcMain
-
-    other-modules: Paths_hpc_bin
+                   Paths_hpc_bin
     autogen-modules: Paths_hpc_bin
 
     build-depends: base       >= 4   && < 5,
@@ -52,13 +53,6 @@ library
     if flag(build-tool-depends)
       build-tool-depends: happy:happy >= 1.20.0
 
-executable hpc
-    default-language: Haskell2010
-    hs-source-dirs: app
-    main-is: Main.hs
-
-    build-depends: base >= 4 && < 5,
-                   hpc-bin
 
 test-suite hpc-test
   type: exitcode-stdio-1.0