Add the InstalledPackageIndex to the LocalBuildInfo

So now all the info about installed packages is available to all the
verious build phases.

Distribution/Simple/Configure.hs

@@ -319,6 +319,7 @@ configure (pkg_descr0, pbi) cfg
                                             (distPref </> "scratch")
                                             (configScratchDir cfg),
 		    packageDeps         = dep_pkgs,
+                    installedPkgs       = packageDependsIndex,
                     pkgDescrFile        = Nothing,
 		    localPkgDescr       = pkg_descr',
 		    withPrograms        = programsConfig''',

Distribution/Simple/LocalBuildInfo.hs

@@ -61,6 +61,7 @@ import Distribution.Simple.Program (ProgramConfiguration)
 import Distribution.PackageDescription (PackageDescription(..))
 import Distribution.Package (PackageIdentifier(..))
 import Distribution.Simple.Compiler (Compiler(..), PackageDB)
+import Distribution.Simple.InstalledPackageIndex (InstalledPackageIndex)
 
 -- |Data cached after configuration step.  See also
 -- 'Distribution.Setup.ConfigFlags'.
@@ -81,6 +82,8 @@ data LocalBuildInfo = LocalBuildInfo {
 		-- that must be satisfied in terms of version ranges.  This
 		-- field fixes those dependencies to the specific versions
 		-- available on this machine for this compiler.
+        installedPkgs :: InstalledPackageIndex,
+                -- ^ All the info about all installed packages.
         pkgDescrFile  :: Maybe FilePath,
                 -- ^ the filename containing the .cabal file, if available
         localPkgDescr :: PackageDescription,