[tests] Additional tests for some checked cast edge cases

Author: LucianoPAlmeida

test/Misc/misc_diagnostics.swift

@@ -170,10 +170,30 @@ func tuple_splat2(_ q : (a : Int, b : Int)) {
 }
 
 // SR-1612: Type comparison of foreign types is always true.
-func is_foreign(a: AnyObject) -> Bool {
+protocol SR1612_P {}
+class SR1612: NSObject, SR1612_P {}
+// Existentials
+func is_foreign_anyobject(a: AnyObject) -> Bool {
   return a is CGColor // expected-warning {{'is' test is always true because 'CGColor' is a Core Foundation type}}
 }
 
+func is_foreign_any(a: Any) -> Bool {
+  return a is CGColor // expected-warning {{'is' test is always true because 'CGColor' is a Core Foundation type}}
+}
+
+func is_foreign_p(a: SR1612_P) -> Bool {
+  return a is CGColor // expected-warning {{'is' test is always true because 'CGColor' is a Core Foundation type}}
+}
+
+// Concrete type.
+func is_foreign_concrete(a: SR1612) -> Bool {
+  return a is CGColor // False at runtime
+}
+// Concrete foundation.
+func is_foreign_s(a: NSString) -> Bool {
+  return a is CGColor // False at runtime
+}
+
 func test_implicit_cgfloat_conversion() {
   func test_to(_: CGFloat) {}
   func test_from(_: Double) {}
@@ -187,14 +207,14 @@ func test_implicit_cgfloat_conversion() {
   test_to(d + d) // Ok (Double -> CGFloat for both arguments)
   test_to(d + cgf) // Ok
   test_to(d + cgf - d) // Ok (prefer CGFloat -> Double for `cgf`), it's a better solution than trying to convert `d`s to `CGFloat`
-  test_to(d + cgf - cgf) // Ok (only one choice here to conver `d` to CGFloat)
+  test_to(d + cgf - cgf) // Ok (only one choice here to convert `d` to CGFloat)
 
   test_from(cgf) // Ok (CGFloat -> Double)
   test_from(f) // expected-error {{cannot convert value of type 'Float' to expected argument type 'Double'}}
   test_from(cgf + cgf) // Ok (CGFloat -> Double for both arguments)
   test_from(d + cgf) // Ok
   test_from(cgf + d - cgf) // (prefer Double -> CGFloat for `d`), it's a better solution than trying to convert `cgf`s to `Double`
-  test_from(cgf + d - d) // Ok (only one choice here to conver `cgf` to Double)
+  test_from(cgf + d - d) // Ok (only one choice here to convert `cgf` to Double)
 
   func test_returns_double(_: CGFloat) -> Double {
     42.0

test/expr/cast/as_coerce.swift

@@ -118,14 +118,18 @@ func sr6022() -> Any { return 0 }
 func sr6022_1() { return; }
 protocol SR6022_P {}
 
+_ = sr6022 is SR6022_P // expected-warning {{cast from '() -> Any' to unrelated type 'any SR6022_P' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'?}}{{11-11=()}}
 _ = sr6022 as! SR6022_P // expected-warning {{cast from '() -> Any' to unrelated type 'any SR6022_P' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'?}}{{11-11=()}}
 _ = sr6022 as? SR6022_P // expected-warning {{cast from '() -> Any' to unrelated type 'any SR6022_P' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'}}{{11-11=()}}
+_ = sr6022_1 is SR6022_P // expected-warning {{cast from '() -> ()' to unrelated type 'any SR6022_P' always fails}}
 _ = sr6022_1 as! SR6022_P // expected-warning {{cast from '() -> ()' to unrelated type 'any SR6022_P' always fails}}
 _ = sr6022_1 as? SR6022_P // expected-warning {{cast from '() -> ()' to unrelated type 'any SR6022_P' always fails}}
 
 func testSR6022_P<T: SR6022_P>(_: T.Type) {
+  _ = sr6022 is T // expected-warning {{cast from '() -> Any' to unrelated type 'T' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'?}}{{13-13=()}}
   _ = sr6022 as! T // expected-warning {{cast from '() -> Any' to unrelated type 'T' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'?}}{{13-13=()}}
   _ = sr6022 as? T // expected-warning {{cast from '() -> Any' to unrelated type 'T' always fails}} // expected-note {{did you mean to call 'sr6022' with '()'?}}{{13-13=()}}
+  _ = sr6022_1 is T // expected-warning {{cast from '() -> ()' to unrelated type 'T' always fails}}
   _ = sr6022_1 as! T // expected-warning {{cast from '() -> ()' to unrelated type 'T' always fails}}
   _ = sr6022_1 as? T // expected-warning {{cast from '() -> ()' to unrelated type 'T' always fails}}
 }