Implement ember's component-template-resolving deprecation

When using embroider with staticComponents enabled, users will never see Ember's [component-template-resolving](https://deprecations.emberjs.com/id/component-template-resolving/) deprecation, since Embroider takes care of implementing the whole feature at build time before Ember can see it at runtime.

This implements the same deprecation logic in Embroider apps so everybody can stay consistent.

packages/core/package.json

@@ -42,6 +42,7 @@
     "lodash": "^4.17.21",
     "resolve": "^1.20.0",
     "resolve-package-path": "^4.0.1",
+    "semver": "^7.3.5",
     "typescript-memoize": "^1.0.1",
     "walk-sync": "^3.0.0"
   },
@@ -59,6 +60,7 @@
     "@types/lodash": "^4.14.170",
     "@types/node": "^15.12.2",
     "@types/resolve": "^1.20.0",
+    "@types/semver": "^7.3.5",
     "@types/tmp": "^0.1.0",
     "fixturify": "^2.1.1",
     "tmp": "^0.1.0",

packages/core/src/module-resolver.ts

@@ -24,6 +24,7 @@ import { Memoize } from 'typescript-memoize';
 import { describeExports } from './describe-exports';
 import { readFileSync } from 'fs';
 import type UserOptions from './options';
+import { satisfies } from 'semver';
 
 const debug = makeDebug('embroider:resolver');
 function logTransition<R extends ModuleRequest>(reason: string, before: R, after: R = before): R {
@@ -513,6 +514,11 @@ export class Resolver {
     }
 
     if (hbsModule) {
+      if (!this.emberVersionSupportsSeparateTemplates) {
+        throw new Error(
+          `Components with separately resolved templates were removed at Ember 6.0. Migrate to either co-located js/ts + hbs files or to gjs/gts. https://deprecations.emberjs.com/id/component-template-resolving/. Bad template was: ${hbsModule}.`
+        );
+      }
       return logTransition(
         `resolveComponent found legacy HBS`,
         request,
@@ -723,6 +729,17 @@ export class Resolver {
     return owningEngine;
   }
 
+  get emberVersion(): string {
+    return this.packageCache.get(this.options.engines[0].root).dependencies.find(d => d.name === 'ember-source')!
+      .version;
+  }
+
+  @Memoize() get emberVersionSupportsSeparateTemplates(): boolean {
+    return satisfies(this.emberVersion, '< 6.0.0-alpha.0', {
+      includePrerelease: true,
+    });
+  }
+
   private handleRewrittenPackages<R extends ModuleRequest>(request: R): R {
     if (request.isVirtual) {
       return request;

packages/core/src/virtual-content.ts

@@ -67,6 +67,22 @@ function renderESExternalShim({ moduleName, exports }: { moduleName: string; exp
 const pairedComponentShim = compile(`
 import { setComponentTemplate } from "@ember/component";
 import template from "{{{js-string-escape relativeHBSModule}}}";
+import { deprecate } from "@ember/debug";
+
+
+deprecate("Components with separately resolved templates are deprecated. Migrate to either co-located js/ts + hbs files or to gjs/gts. Tried to lookup '{{debugName}}'.",
+  false, {
+    id: 'component-template-resolving',
+    url: 'https://deprecations.emberjs.com/id/component-template-resolving',
+    until: '6.0.0',
+    for: 'ember-source',
+    since: {
+      available: '5.10.0',
+      enabled: '5.10.0',
+    },
+  }
+);
+
 {{#if relativeJSModule}}
 import component from "{{{js-string-escape relativeJSModule}}}";
 export default setComponentTemplate(template, component);