refactor(core): combine TestBed interface and implementation to avoid…

… cycles

This commit combines TestBed interface and implementation to avoid cycles in the import graph. There are no functional or API changes.

goldens/circular-deps/packages.json

@@ -162,14 +162,6 @@
     "packages/core/src/render3/interfaces/query.ts",
     "packages/core/src/render3/interfaces/view.ts"
   ],
-  [
-    "packages/core/testing/src/test_bed_common.ts",
-    "packages/core/testing/src/test_bed.ts"
-  ],
-  [
-    "packages/core/testing/src/test_bed_impl.ts",
-    "packages/core/testing/src/test_bed.ts"
-  ],
   [
     "packages/forms/src/directives.ts",
     "packages/forms/src/directives/ng_control_status.ts",

packages/core/test/test_bed_spec.ts

@@ -7,8 +7,7 @@
  */
 
 import {APP_INITIALIZER, ChangeDetectorRef, Compiler, Component, Directive, ElementRef, ErrorHandler, getNgModuleById, Inject, Injectable, InjectionToken, Injector, Input, LOCALE_ID, ModuleWithProviders, NgModule, Optional, Pipe, Type, ViewChild, ɵsetClassMetadata as setClassMetadata, ɵɵdefineComponent as defineComponent, ɵɵdefineInjector as defineInjector, ɵɵdefineNgModule as defineNgModule, ɵɵelementEnd as elementEnd, ɵɵelementStart as elementStart, ɵɵsetNgModuleScope as setNgModuleScope, ɵɵtext as text} from '@angular/core';
-import {TestBed} from '@angular/core/testing/src/test_bed';
-import {TestBedImpl} from '@angular/core/testing/src/test_bed_impl';
+import {TestBed, TestBedImpl} from '@angular/core/testing/src/test_bed';
 import {By} from '@angular/platform-browser';
 import {expect} from '@angular/platform-browser/testing/src/matchers';