perf(@ngtools/webpack): reduce repeat path mapping analysis during resolution
perf(@ngtools/webpack): reduce repeat path mapping analysis during resolution

The internal TypeScript path mapping Webpack resolver plugin is used to adjust module resolution during builds via the TypeScript configuration `paths` option. Prior to a build, the `paths` option is now preprocessed to limit the amount of analysis that is needed within each individual module resolution attempt during a build. Since module resolution attempts can occur frequently during a build, this change offers the potential to reduce the total cost of module resolution especially for applications with a large amount of configured path mappings.

geofffilippi/angular-cli,geofffilippi/angular-cli,catull/angular-cli,Brocco/angular-cli,angular/angular-cli,catull/angular-cli,Brocco/angular-cli,Brocco/angular-cli,catull/angular-cli,Brocco/angular-cli,Brocco/angular-cli,angular/angular-cli,geofffilippi/angular-cli,angular/angular-cli,clydin/angular-cli,catull/angular-cli,geofffilippi/angular-cli,clydin/angular-cli,clydin/angular-cli,clydin/angular-cli,angular/angular-cli