refactor(@angular-devkit/build-optimizer): remove errant deprecations

These functions are not public and are also used internally.

Author: clydin

packages/angular_devkit/build_optimizer/src/transforms/prefix-classes.ts

@@ -8,9 +8,6 @@
 import * as ts from 'typescript';
 import { addPureComment } from '../helpers/ast-utils';
 
-/**
- * @deprecated From 0.9.0
- */
 export function testPrefixClasses(content: string) {
   const exportVarSetter = /(?:export )?(?:var|const)\s+(?:\S+)\s*=\s*/;
   const multiLineComment = /\s*(?:\/\*[\s\S]*?\*\/)?\s*/;

packages/angular_devkit/build_optimizer/src/transforms/scrub-file.ts

@@ -8,9 +8,6 @@
 import * as ts from 'typescript';
 import { collectDeepNodes } from '../helpers/ast-utils';
 
-/**
- * @deprecated From 0.9.0
- */
 export function testScrubFile(content: string) {
   const markers = [
     'decorators',