[stdlib] Change C-style for loop to Swift-style for-in loop

stdlib/public/core/HashedCollections.swift.gyb

@@ -713,15 +713,18 @@ public func == <Element : Hashable>(lhs: Set<Element>, rhs: Set<Element>) -> Boo
     }
 
     let endIndex = lhsNative.endIndex
-    for var i = lhsNative.startIndex; i != endIndex; i = i.successor() {
+    var i = lhsNative.startIndex
+    while i != endIndex {
       let key = lhsNative.assertingGet(i)
       let bridgedKey: AnyObject = _bridgeToObjectiveCUnconditional(key)
       let optRhsValue: AnyObject? = rhsCocoa.maybeGet(bridgedKey)
       if let rhsValue = optRhsValue {
         if key == _forceBridgeFromObjectiveC(rhsValue, Element.self) {
+          i = i.successor()
           continue
         }
       }
+      i = i.successor()
       return false
     }
     return true
@@ -1230,16 +1233,18 @@ public func == <Key : Equatable, Value : Equatable>(
     }
 
     let endIndex = lhsNative.endIndex
-    for var index = lhsNative.startIndex; index != endIndex;
-        index._successorInPlace() {
+    var index = lhsNative.startIndex
+    while index != endIndex {
       let (key, value) = lhsNative.assertingGet(index)
       let optRhsValue: AnyObject? =
         rhsCocoa.maybeGet(_bridgeToObjectiveCUnconditional(key))
       if let rhsValue = optRhsValue {
         if value == _forceBridgeFromObjectiveC(rhsValue, Value.self) {
+          index._successorInPlace()
           continue
         }
       }
+      index._successorInPlace()
       return false
     }
     return true
@@ -2113,7 +2118,7 @@ struct _Native${Self}Storage<${TypeParametersDecl}> :
   var description: String {
     var result = ""
 #if INTERNAL_CHECKS_ENABLED
-    for var i = 0; i != capacity; i += 1 {
+    for i in 0..<capacity {
       if isInitializedEntry(i) {
         let key = keyAt(i)
         result += "bucket \(i), ideal bucket = \(_bucket(key)), key = \(key)\n"
@@ -2601,7 +2606,7 @@ final internal class _Native${Self}StorageOwner<${TypeParametersDecl}>
     let bridged = _createBridgedNativeStorage(nativeStorage.capacity)
 
     // Bridge everything.
-    for var i = 0; i < nativeStorage.capacity; i += 1 {
+    for i in 0..<nativeStorage.capacity {
       if nativeStorage.isInitializedEntry(i) {
         let key = _bridgeToObjectiveCUnconditional(nativeStorage.keyAt(i))
 %if Self == 'Set':
@@ -3248,10 +3253,10 @@ internal enum _Variant${Self}Storage<${TypeParametersDecl}> : _HashStorageType {
 
     // Find the last bucket in the contiguous chain
     var lastInChain = hole
-    for var b = nativeStorage._next(lastInChain);
-      nativeStorage.isInitializedEntry(b);
-      b = nativeStorage._next(b) {
+    var b = nativeStorage._next(lastInChain)
+    while nativeStorage.isInitializedEntry(b) {
       lastInChain = b
+      b = nativeStorage._next(b)
     }
 
     // Relocate out-of-place elements in the chain, repeating until
@@ -3259,8 +3264,8 @@ internal enum _Variant${Self}Storage<${TypeParametersDecl}> : _HashStorageType {
     while hole != lastInChain {
       // Walk backwards from the end of the chain looking for
       // something out-of-place.
-      var b: Int
-      for b = lastInChain; b != hole; b = nativeStorage._prev(b) {
+      var b = lastInChain
+      while b != hole {
         let idealBucket = nativeStorage._bucket(nativeStorage.keyAt(b))
 
         // Does this element belong between start and hole?  We need
@@ -3271,6 +3276,7 @@ internal enum _Variant${Self}Storage<${TypeParametersDecl}> : _HashStorageType {
         if start <= hole ? (c0 && c1) : (c0 || c1) {
           break // Found it
         }
+        b = nativeStorage._prev(b)
       }
 
       if b == hole { // No out-of-place elements found; we're done adjusting
@@ -3409,7 +3415,7 @@ internal enum _Variant${Self}Storage<${TypeParametersDecl}> : _HashStorageType {
       nativeStorage = native
     }
 
-    for var b = 0; b != nativeStorage.capacity; b  += 1 {
+    for b in 0..<nativeStorage.capacity {
       if nativeStorage.isInitializedEntry(b) {
         nativeStorage.destroyEntryAt(b)
       }