Restore output of number of packages analyzed in solver

src/Composer/Installer.php

@@ -491,6 +491,7 @@ class Installer
 
         $this->eventDispatcher->dispatchInstallerEvent(InstallerEvents::POST_DEPENDENCIES_SOLVING, $this->devMode, $policy, $repositorySet, $installedRepo, $request, $operations);
 
+        $this->io->writeError("Analyzed ".count($pool)." packages to resolve dependencies", true, IOInterface::VERBOSE);
         $this->io->writeError("Analyzed ".$solver->getRuleSetSize()." rules to resolve dependencies", true, IOInterface::VERBOSE);
 
         // execute operations