Add regression tests to close some issues

test/IRGen/recursion_infinite_optimized.sil

@@ -0,0 +1,22 @@
+// RUN: %target-swift-emit-ir %s -O | %FileCheck %s
+
+// https://github.com/apple/swift/issues/43069
+
+sil_stage canonical
+
+import Swift
+
+sil @rec : $@convention(thin) (Int) -> Int {
+bb0(%arg : $Int):
+  %ref = function_ref @rec : $@convention(thin) (Int) -> Int
+  %res = apply %ref(%arg) : $@convention(thin) (Int) -> Int
+  return %res : $Int
+}
+
+// CHECK: define{{.*}} swiftcc [[T:i[0-9]+]] @rec([[T]] %0) #0 {
+// CHECK-NEXT: entry:
+// CHECK-NEXT: br label %tailrecurse
+// CHECK-EMPTY:
+// CHECK-NEXT: tailrecurse:
+// CHECK-NEXT: br label %tailrecurse
+// CHECK-NEXT: }

test/Interpreter/collection_casts.swift

@@ -73,6 +73,12 @@ a_array_3?.forEach { $0.preen() }
 // CHECK-NEXT: A10
 // CHECK-NEXT: A20
 
+let a_array_4 = preening_array_1 as! [A]
+a_array_4.forEach { $0.preen() }
+// CHECK-NEXT: A5
+// CHECK-NEXT: A10
+// CHECK-NEXT: A20
+
 }
 
 do {

test/decl/protocol/protocol_with_superclass.swift

@@ -351,3 +351,12 @@ func usesProtoRefinesClass2<T : ProtoRefinesClassComposition>(_ t: T) {
   t.genericMethod((1, 2))
   let _: BaseProto = t
 }
+
+// https://github.com/apple/swift/issues/52883
+class issue52883_C: issue52883_P {}
+protocol issue52883_P: issue52883_C {
+  func foo()
+}
+extension issue52883_P {
+  func foo() {}
+}

test/expr/closure/inference.swift

@@ -77,3 +77,12 @@ cc(1) // Ok
 func SR12955() {
   let f: @convention(c) (T) -> Void // expected-error {{cannot find type 'T' in scope}}
 }
+
+// https://github.com/apple/swift/issues/42790
+do {
+  func foo<T>(block: () -> ()) -> T.Type { T.self } // expected-note {{in call to function 'foo(block:)'}}
+
+  let x = foo { // expected-error {{generic parameter 'T' could not be inferred}}
+    print("")
+  }
+}

validation-test/compiler_crashers_2_fixed/issue59572.swift

@@ -0,0 +1,9 @@
+// RUN: %target-swift-emit-ir %s
+
+// https://github.com/apple/swift/issues/59572
+
+func foo<T: RawRepresentable>(src: Any, target: inout T) where T.RawValue == UInt {
+  if let x = src as? UInt, let x = T(rawValue: x) {
+    target = x
+  }
+}