fix(@ngtools/webpack): remove compiler workarounds

These issues were fixed in Angular 5.0.0-rc.7.

Author: filipesilva

packages/@ngtools/webpack/src/angular_compiler_plugin.ts

@@ -372,26 +372,19 @@ export class AngularCompilerPlugin implements Tapable {
         } else {
           time('AngularCompilerPlugin._createOrUpdateProgram.ng.createProgram');
           // Create the Angular program.
-          try {
-            this._program = createProgram({
-              rootNames: this._tsFilenames,
-              options: this._angularCompilerOptions,
-              host: this._angularCompilerHost,
-              oldProgram: this._program as Program
+          this._program = createProgram({
+            rootNames: this._tsFilenames,
+            options: this._angularCompilerOptions,
+            host: this._angularCompilerHost,
+            oldProgram: this._program as Program
+          });
+          timeEnd('AngularCompilerPlugin._createOrUpdateProgram.ng.createProgram');
+
+          time('AngularCompilerPlugin._createOrUpdateProgram.ng.loadNgStructureAsync');
+          return this._program.loadNgStructureAsync()
+            .then(() => {
+              timeEnd('AngularCompilerPlugin._createOrUpdateProgram.ng.loadNgStructureAsync');
             });
-            timeEnd('AngularCompilerPlugin._createOrUpdateProgram.ng.createProgram');
-
-            time('AngularCompilerPlugin._createOrUpdateProgram.ng.loadNgStructureAsync');
-            return this._program.loadNgStructureAsync()
-              .then(() => {
-                timeEnd('AngularCompilerPlugin._createOrUpdateProgram.ng.loadNgStructureAsync');
-              });
-          } catch (e) {
-            // TODO: remove this when the issue is addressed.
-            // Temporary workaround for https://github.com/angular/angular/issues/19951
-            this._program = undefined;
-            throw e;
-          }
         }
       })
       .then(() => {
@@ -731,10 +724,6 @@ export class AngularCompilerPlugin implements Tapable {
         const changedTsFiles = this._getChangedTsFiles();
         if (this._ngCompilerSupportsNewApi) {
           this._processLazyRoutes(this._listLazyRoutesFromProgram());
-          // TODO: remove this when the issue is addressed.
-          // Fix for a bug in compiler where the program needs to be updated after
-          // _listLazyRoutesFromProgram is called.
-          return this._createOrUpdateProgram();
         } else if (this._firstRun) {
           this._processLazyRoutes(this._getLazyRoutesFromNgtools());
         } else if (changedTsFiles.length > 0) {
@@ -1002,9 +991,6 @@ export class AngularCompilerPlugin implements Tapable {
             this.writeI18nOutFile();
           }
           timeEnd('AngularCompilerPlugin._emit.ng.emit');
-        } else {
-          // Throw away the old program if there was an error.
-          this._program = undefined;
         }
       }
     } catch (e) {