Optimize ReplaceAliasByActualDefinitionPass
Optimize ReplaceAliasByActualDefinitionPass

Previous implementation passed over every alias and every definition, for every
alias (n*(n+m) runtime). New implementation passes once over all aliases and
once over all definitions (n+m).

Also removing needless "restart" logic --- it has no real effect in either case.

symfony/dependency-injection,symfony/DependencyInjection