Remove Darwin module's dependency on ctypes.h

Upstream cfe change r284797 requires that the Darwin module only depend
on its submodules. This means it cannot depend on ctypes, so we need
to split up this dependency in the swift test suite.

Author: fjricci

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

@@ -5,7 +5,7 @@ typedef struct CGPoint CGPoint;
 typedef CGPoint NSPoint;
 NSString *NSStringToNSString(NSString *str);
 
-struct FooStruct1 {
+struct FooStructA {
   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: Point) -> Point {
+public func testStruct(_ p: Darwin.Point) -> Darwin.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(Point(x: 2,y: 3))
+  _ = testStruct(Darwin.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: Point) -> Point {
+func testStruct(_ p: Darwin.Point) -> Darwin.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.FooStruct1 = AppKit.FooStruct1()
+let viaStruct: Redeclaration.FooStructA = AppKit.FooStructA()
 let forwardDecl: Redeclaration.Tribool = AppKit.Tribool() // expected-error {{no type named 'Tribool' in module 'Redeclaration'}}

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

@@ -1,7 +1,44 @@
 #ifndef __MACTYPES__
 #define __MACTYPES__
 
-#include "ctypes.h"
+#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;
+};
 
 typedef SInt32                          Fixed;
 typedef Fixed *                         FixedPtr;

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

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