fix(runtime-core): fix SSR memoery leak due to props normalization cache

fix #2225

The previous props/emits normlaization was caching normalized result per
app instance, but during SSR there is a new app instance created for
every request.

The fix now de-opts props/emits normlaization caching when there are
props/emits declared in global mixins - which is a very rare use case.

packages/runtime-core/src/apiCreateApp.ts

@@ -74,7 +74,16 @@ export interface AppContext {
   components: Record<string, Component>
   directives: Record<string, Directive>
   provides: Record<string | symbol, any>
-  reload?: () => void // HMR only
+  /**
+   * Flag for de-optimizing props normalization
+   * @internal
+   */
+  deopt?: boolean
+  /**
+   * HMR only
+   * @internal
+   */
+  reload?: () => void
 }
 
 type PluginInstallFunction = (app: App, ...options: any[]) => any
@@ -169,6 +178,11 @@ export function createAppAPI<HostElement>(
         if (__FEATURE_OPTIONS_API__) {
           if (!context.mixins.includes(mixin)) {
             context.mixins.push(mixin)
+            // global mixin with props/emits de-optimizes props/emits
+            // normalization caching.
+            if (mixin.props || mixin.emits) {
+              context.deopt = true
+            }
           } else if (__DEV__) {
             warn(
               'Mixin has already been applied to target app' +