perf: delete pre-view-engine core, compiler, platform-browser, etc code (#14788)

After the introduction of the view engine, we can drop a lot of code that is not used any more.

This should reduce the size of the app bundles because a lot of this code was not being properly tree-shaken by today's tools even though it was dead code.

modules/@angular/compiler/src/ng_module_compiler.ts

@@ -9,7 +9,6 @@
 import {ɵLifecycleHooks} from '@angular/core';
 
 import {CompileDiDependencyMetadata, CompileIdentifierMetadata, CompileNgModuleMetadata, CompileProviderMetadata, CompileTokenMetadata, identifierModuleUrl, identifierName, tokenName, tokenReference} from './compile_metadata';
-import {createDiTokenExpression} from './compiler_util/identifier_util';
 import {isPresent} from './facade/lang';
 import {Identifiers, createIdentifier, resolveIdentifier} from './identifiers';
 import {CompilerInjectable} from './injectable';
@@ -239,6 +238,14 @@ class _InjectorBuilder implements ClassBuilder {
   }
 }
 
+function createDiTokenExpression(token: CompileTokenMetadata): o.Expression {
+  if (isPresent(token.value)) {
+    return o.literal(token.value);
+  } else {
+    return o.importExpr(token.identifier);
+  }
+}
+
 class InjectorProps {
   static parent = o.THIS_EXPR.prop('parent');
 }