build: export runtime-only build for bundlers by default in main vue package

packages/vue/package.json

@@ -3,7 +3,7 @@
   "version": "3.0.0-alpha.0",
   "description": "vue",
   "main": "index.js",
-  "module": "dist/vue.esm-bundler.js",
+  "module": "dist/vue.runtime.esm-bundler.js",
   "files": [
     "index.js",
     "dist"
@@ -14,6 +14,7 @@
     "name": "Vue",
     "formats": [
       "esm-bundler",
+      "esm-bundler-runtime",
       "cjs",
       "global",
       "esm"

packages/vue/src/devCheck.ts

@@ -0,0 +1,6 @@
+if (__BROWSER__ && __DEV__) {
+  console[console.info ? 'info' : 'log'](
+    `You are running a development build of Vue.\n` +
+      `Make sure to use the production build (*.prod.js) when deploying for production.`
+  )
+}

packages/vue/src/index.ts

@@ -1,4 +1,4 @@
-// This package is the "full-build" that includes both the runtime
+// This entry is the "full-build" that includes both the runtime
 // and the compiler, and supports on-the-fly compilation of the template option.
 import { compile, CompilerOptions, CompilerError } from '@vue/compiler-dom'
 import { registerRuntimeCompiler, RenderFunction, warn } from '@vue/runtime-dom'
@@ -61,9 +61,4 @@ registerRuntimeCompiler(compileToFunction)
 export { compileToFunction as compile }
 export * from '@vue/runtime-dom'
 
-if (__BROWSER__ && __DEV__) {
-  console[console.info ? 'info' : 'log'](
-    `You are running a development build of Vue.\n` +
-      `Make sure to use the production build (*.prod.js) when deploying for production.`
-  )
-}
+import './devCheck'

packages/vue/src/runtime.ts

@@ -0,0 +1,6 @@
+// This entry exports the runtime only, and is built as
+// `dist/vue.esm-bundler.js` which is used by default for bundlers.
+
+export * from '@vue/runtime-dom'
+
+import './devCheck'