[Diagnostics] Remove the warning for 'any Any' and 'any AnyObject'.

Author: hborla

include/swift/AST/DiagnosticsSema.def

@@ -4643,8 +4643,6 @@ ERROR(unchecked_not_inheritance_clause,none,
 ERROR(unchecked_not_existential,none,
       "'unchecked' attribute cannot apply to non-protocol type %0", (Type))
 
-WARNING(unnecessary_any,none,
-         "'any' is redundant on type %0", (Type))
 ERROR(any_not_existential,none,
        "'any' has no effect on %select{concrete type|type parameter}0 %1",
        (bool, Type))

lib/Sema/TypeCheckType.cpp

@@ -3783,13 +3783,6 @@ TypeResolver::resolveExistentialType(ExistentialTypeRepr *repr,
     return constraintType;
   }
 
-  // Warn about `any Any` and `any AnyObject`.
-  if (constraintType->isAny() || constraintType->isAnyObject()) {
-    diagnose(repr->getLoc(), diag::unnecessary_any,
-             constraintType)
-      .fixItRemove({anyStart, anyEnd});
-  }
-
   return ExistentialType::get(constraintType);
 }
 

test/type/explicit_existential.swift

@@ -149,9 +149,9 @@ func testInvalidAny() {
   let _: any ((S) -> Void) = generic // expected-error{{'any' has no effect on concrete type '(S) -> Void'}}
 }
 
-func testRedundantAnyWarning() {
-  let _: any Any // expected-warning {{'any' is redundant on type 'Any'}}
-  let _: any AnyObject // expected-warning {{'any' is redundant on type 'AnyObject'}}
+func anyAny() {
+  let _: any Any
+  let _: any AnyObject
 }
 
 protocol P1 {}