refactor(core): make lockRunMode a noop and deprecate it.

BREAKING CHANGE:
- `lockRunMode` is deprecated and no more needed.

Closes #9878

modules/@angular/compiler-cli/src/codegen.ts

@@ -11,7 +11,7 @@
  * Intended to be used in a build step.
  */
 import * as compiler from '@angular/compiler';
-import {AppModuleMetadata, ComponentMetadata, ViewEncapsulation, lockRunMode} from '@angular/core';
+import {AppModuleMetadata, ComponentMetadata, ViewEncapsulation} from '@angular/core';
 import {AngularCompilerOptions} from '@angular/tsc-wrapped';
 import * as path from 'path';
 import * as ts from 'typescript';
@@ -36,9 +36,7 @@ export class CodeGenerator {
       private options: AngularCompilerOptions, private program: ts.Program,
       public host: ts.CompilerHost, private staticReflector: StaticReflector,
       private resolver: CompileMetadataResolver, private compiler: compiler.OfflineCompiler,
-      private reflectorHost: ReflectorHost) {
-    lockRunMode();
-  }
+      private reflectorHost: ReflectorHost) {}
 
   private readFileMetadata(absSourcePath: string): FileMetadata {
     const moduleMetadata = this.staticReflector.getModuleMetadata(absSourcePath);