Revert "Remove Darwin module's dependency on ctypes.h"

This reverts commit 24591ef.

This is slightly different than the commit on master. Reverting prior
to merging in master.

Author: bob-wilson

test/ClangModules/Inputs/custom-modules/Redeclaration.h

@@ -5,7 +5,7 @@ typedef struct CGPoint CGPoint;
 typedef CGPoint NSPoint;
 NSString *NSStringToNSString(NSString *str);
 
-struct FooStructA {
+struct FooStruct1 {
   int x;
   double y;
 };

test/ClangModules/MixedSource/Inputs/mixed-with-header.swift

@@ -24,7 +24,7 @@ public func testProtocolWrapper(_ conformer: ForwardClassUser) {
    conformer.consumeForwardClass(conformer.forward)
 }
 
-public func testStruct(_ p: Darwin.Point) -> Darwin.Point {
+public func testStruct(_ p: Point) -> Point {
    var result = p
    result.y += 5
    return result

test/ClangModules/MixedSource/import-mixed-with-header.swift

@@ -27,5 +27,5 @@ func testCrossReferences(_ derived: Derived) {
   _ = obj.safeOverrideProto(ForwardProtoAdopter()) as NSObject
 
   testProtocolWrapper(ProtoConformer())
-  _ = testStruct(Darwin.Point(x: 2,y: 3))
+  _ = testStruct(Point(x: 2,y: 3))
 }

test/ClangModules/MixedSource/mixed-target-using-header.swift

@@ -39,7 +39,7 @@ func testProtocolWrapper(_ conformer: ForwardClassUser) {
 }
 testProtocolWrapper(ProtoConformer())
 
-func testStruct(_ p: Darwin.Point) -> Darwin.Point {
+func testStruct(_ p: Point) -> Point {
   var result = p
   result.y += 5
   return result

test/ClangModules/adapter.swift

@@ -17,5 +17,5 @@ let encoding: UInt = NSUTF8StringEncoding
 let viaTypedef: Redeclaration.NSPoint = AppKit.NSPoint(x: 0, y: 0)
 Redeclaration.NSStringToNSString(AppKit.NSStringToNSString("abc")) // expected-warning {{result of call is unused}}
 
-let viaStruct: Redeclaration.FooStructA = AppKit.FooStructA()
+let viaStruct: Redeclaration.FooStruct1 = AppKit.FooStruct1()
 let forwardDecl: Redeclaration.Tribool = AppKit.Tribool() // expected-error {{no type named 'Tribool' in module 'Redeclaration'}}

test/Inputs/clang-importer-sdk/usr/include/MacTypes.h

@@ -1,44 +1,7 @@
 #ifndef __MACTYPES__
 #define __MACTYPES__
 
-#define STDLIB_TEST(TYPE, NAME) extern NAME NAME##_test
-#define STDLIB_TYPEDEF(TYPE, NAME) \
-  typedef TYPE NAME; \
-  STDLIB_TEST(TYPE, NAME)
-
-STDLIB_TYPEDEF(__INT8_TYPE__, SInt8);
-STDLIB_TYPEDEF(__INT16_TYPE__, SInt16);
-STDLIB_TYPEDEF(__INT32_TYPE__, SInt32);
-
-STDLIB_TYPEDEF(__UINT8_TYPE__, UInt8);
-STDLIB_TYPEDEF(__UINT16_TYPE__, UInt16);
-STDLIB_TYPEDEF(__UINT32_TYPE__, UInt32);
-
-#include <stdint.h>
-
-#if !defined(__have_Point)
-#define __have_Point
-struct Point {
-  float x;
-  float y;
-};
-#endif
-
-/*!
-  @keyword FooA, StructA
-*/
-struct FooStructA {
-  /*!
-  @keyword x, StructA
-  @recommended y
-  */
-  int x;
-  /*!
-  @keyword y, StructA
-  @recommendedover x
-  */
-  double y;
-};
+#include "ctypes.h"
 
 typedef SInt32                          Fixed;
 typedef Fixed *                         FixedPtr;

test/Inputs/clang-importer-sdk/usr/include/ctypes.h

@@ -17,13 +17,10 @@ enum {
   AnonConstSmall2
 };
 
-#if !defined(__have_Point)
-#define __have_Point
 struct Point {
   float x;
   float y;
 };
-#endif
 
 typedef struct {
   struct {