Add end-to-end cabal-install test for "build-tool-depends"

Modeled after the extern_build_tools test

cabal-install/cabal-install.cabal

@@ -85,6 +85,12 @@ Extra-Source-Files:
   tests/IntegrationTests/new-build/T4017/cabal.project
   tests/IntegrationTests/new-build/T4017/p/p.cabal
   tests/IntegrationTests/new-build/T4017/q/q.cabal
+  tests/IntegrationTests/new-build/build_tool_depends.sh
+  tests/IntegrationTests/new-build/build_tool_depends/cabal.project
+  tests/IntegrationTests/new-build/build_tool_depends/client/Hello.hs
+  tests/IntegrationTests/new-build/build_tool_depends/client/client.cabal
+  tests/IntegrationTests/new-build/build_tool_depends/pre-proc/MyCustomPreprocessor.hs
+  tests/IntegrationTests/new-build/build_tool_depends/pre-proc/pre-proc.cabal
   tests/IntegrationTests/new-build/executable/Main.hs
   tests/IntegrationTests/new-build/executable/Setup.hs
   tests/IntegrationTests/new-build/executable/Test.hs

cabal-install/tests/IntegrationTests/new-build/build_tool_depends.sh

+. ./common.sh
+cd build_tool_depends
+cabal new-build client

cabal-install/tests/IntegrationTests/new-build/build_tool_depends/cabal.project

+packages: client, pre-proc

cabal-install/tests/IntegrationTests/new-build/build_tool_depends/client/Hello.hs

+{-# OPTIONS_GHC -F -pgmF zero-to-one #-}
+module Main where
+
+a :: String
+a = "0000"
+
+main :: IO ()
+main = putStrLn a

cabal-install/tests/IntegrationTests/new-build/build_tool_depends/client/client.cabal

+name:                client
+version:             0.1.0.0
+synopsis:            Checks build-tool-depends are put in PATH
+license:             BSD3
+category:            Testing
+build-type:          Simple
+cabal-version:       >=1.10
+
+executable             hello-world
+  main-is:             Hello.hs
+  build-depends:       base
+  build-tool-depends:  pre-proc:zero-to-one
+  default-language:    Haskell2010

cabal-install/tests/IntegrationTests/new-build/build_tool_depends/pre-proc/MyCustomPreprocessor.hs

+module Main where
+
+import System.Environment
+import System.IO
+
+main :: IO ()
+main = do
+  (_:source:target:_) <- getArgs
+  let f '0' = '1'
+      f c = c
+  writeFile target . map f  =<< readFile source

cabal-install/tests/IntegrationTests/new-build/build_tool_depends/pre-proc/pre-proc.cabal

+name:                pre-proc
+version:             999.999.999
+synopsis:            Checks build-tool-depends are put in PATH
+license:             BSD3
+category:            Testing
+build-type:          Simple
+cabal-version:       >=1.10
+
+executable             zero-to-one
+  main-is:             MyCustomPreprocessor.hs
+  build-depends:       base, directory
+  default-language:    Haskell2010