Make benchmarks work on macOS

Author: axman6

benchmark/bench.hs benchmark/Main.hsbenchmark/bench.hs renamed to benchmark/Main.hs

@@ -1,3 +1,5 @@
+module Main where
+
 import Data.Complex
 import Statistics.Sample
 import Statistics.Transform

statistics.cabal

@@ -224,7 +224,7 @@ benchmark statistics-bench
   import:         bench-stanza
   type:           exitcode-stdio-1.0
   hs-source-dirs: benchmark bench-time
-  main-is:        bench.hs
+  main-is:        Main.hs
   Other-modules:  Bench
   build-depends:  tasty-bench >= 0.3
 
@@ -234,6 +234,6 @@ benchmark statistics-bench-papi
   if impl(ghcjs) || !flag(BenchPAPI)
      buildable: False
   hs-source-dirs: benchmark bench-papi
-  main-is:        bench.hs
+  main-is:        Main.hs
   Other-modules:  Bench
   build-depends:  tasty-papi >= 0.1.2