[embedded] Allow casting to tuples

Author: aschwaighofer

SwiftCompilerSources/Sources/Optimizer/Utilities/OptUtils.swift

@@ -1010,8 +1010,7 @@ func isCastSupportedInEmbeddedSwift(from sourceType: Type,
     return false
   }
 
-  // Tuple?
-  if !destType.isStruct && !destType.isClass && !destType.isEnum {
+  if !destType.isStruct && !destType.isClass && !destType.isEnum && !destType.isTuple {
     return false
   }
 

test/embedded/existential.swift

@@ -258,6 +258,17 @@ func test11(_ p: any Any) {
   let c = p as! SubClass
   c.foo()
 }
+
+func test12(_ p: any Any) {
+  print("test any as! (Int, Int, Int, Int)")
+  if let c = p as? (Int, Int, Int, Int) {
+    print("success")
+    print("tuple: \(c.0)")
+  } else {
+    print("cast failed")
+  }
+}
+
 @main
 struct Main {
   static func main() {
@@ -372,5 +383,9 @@ struct Main {
 // OUTPUT:  SubClass.foo
 // OUTPUT:  BaseClass.deinit
 // OUTPUT-NOT:  deinit
+    test12((0, 1, 2, 3))
+// OUTPUT: test any as! (Int, Int, Int, Int)
+// OUTPUT:   success
+// OUTPUT:   tuple: 0
   }
 }