Build for OSX with build script - create dynamic library

'PortableFoundation' Changed swift build dir environment variable;
'SDKROOT' conflicts with xcrun, is now 'SWIFT_SDKROOT'. Requires
updating swift's build script.

Author: springsup

CoreFoundation/Base.subproj/CFAvailability.h

@@ -89,6 +89,29 @@
 #define CF_DEPRECATED_IOS(_iosIntro, _iosDep, ...)
 #endif
 
+#if DEPLOYMENT_RUNTIME_SWIFT
+// PortableFoundation is a standalone module and does not depend on system version
+#undef CF_AVAILABLE
+#undef CF_AVAILABLE_MAC
+#undef CF_AVAILABLE_IOS
+#undef CF_DEPRECATED
+#undef CF_DEPRECATED_MAC
+#undef CF_DEPRECATED_IOS
+
+#define CF_AVAILABLE(_mac, _ios)
+#define CF_AVAILABLE_MAC(_mac)
+#define CF_AVAILABLE_IOS(_ios)
+
+#if __has_attribute(deprecated) // Keep deprecation warnings
+#define CF_DEPRECATED(_macIntro, _macDep, _iosIntro, _iosDep, ...) __attribute__((deprecated(__VA_ARGS__)))
+#else
+#define CF_DEPRECATED(_macIntro, _macDep, _iosIntro, _iosDep, ...)
+#endif
+
+#define CF_DEPRECATED_MAC(_macIntro, _macDep, ...) CF_DEPRECATED(_macIntro, _macDep, 0, 0, __VA_ARGS__)
+#define CF_DEPRECATED_IOS(_iosIntro, _iosDep, ...) CF_DEPRECATED(0, 0, _iosIntro, _iosDep, __VA_ARGS__)
+#endif
+
 // Older versions of these macros; use iOS versions instead
 #define CF_AVAILABLE_IPHONE(_ios) CF_AVAILABLE_IOS(_ios)
 #define CF_DEPRECATED_IPHONE(_iosIntro, _iosDep) CF_DEPRECATED_IOS(_iosIntro, _iosDep)

CoreFoundation/Base.subproj/CFRuntime.c

@@ -1051,7 +1051,7 @@ void __CFInitialize(void) {
         #if TARGET_OS_LINUX
         #define __CFSwiftGetBaseClass _TF10Foundation21__CFSwiftGetBaseClassFT_PMPs9AnyObject_
         #elif TARGET_OS_MAC
-        #define __CFSwiftGetBaseClass _TF15SwiftFoundation21__CFSwiftGetBaseClassFT_PMPs9AnyObject_
+        #define __CFSwiftGetBaseClass _TF18PortableFoundation21__CFSwiftGetBaseClassFT_PMPs9AnyObject_
         #endif
         #endif
         extern uintptr_t __CFSwiftGetBaseClass();        
@@ -1164,7 +1164,7 @@ void __CFInitialize(void) {
         #if TARGET_OS_LINUX
         #define __CFInitializeSwift _TF10Foundation19__CFInitializeSwiftFT_T_
         #elif TARGET_OS_MAC
-        #define __CFInitializeSwift _TF15SwiftFoundation19__CFInitializeSwiftFT_T_
+        #define __CFInitializeSwift _TF18PortableFoundation19__CFInitializeSwiftFT_T_
         #endif
         #endif
         extern void __CFInitializeSwift();

CoreFoundation/Base.subproj/DarwinSymbolAliases

@@ -1,7 +1,7 @@
 
 
 # This is specific to Swift open source; Foundation's NSCFConstantString is used as our constant string class reference
-__TMC15SwiftFoundation19_NSCFConstantString ___CFConstantStringClassReference
+__TMC18PortableFoundation19_NSCFConstantString ___CFConstantStringClassReference
 
 _kCFCalendarIdentifierBuddhist		_kCFBuddhistCalendar
 _kCFCalendarIdentifierChinese		_kCFChineseCalendar

CoreFoundation/Base.subproj/SymbolAliases

@@ -25,7 +25,7 @@ Build and test steps:
 
 0. Run Xcode with the latest toolchain. Follow [the instructions here](https://swift.org/download/#apple-platforms) to start Xcode with the correct toolchain.
 0. Open `Foundation.xcworkspace`.
-0. Build the _SwiftFoundation_ target. This builds CoreFoundation and Foundation.
+0. Build the _PortableFoundation_ target. This builds CoreFoundation and Foundation.
 0. Run (Cmd-R) the _TestFoundation_ target. This builds CoreFoundation, Foundation, XCTest, and TestFoundation, then runs the tests.
 
 > Note: If you see the name of the XCTest project file in red in the workspace, then Xcode cannot find the cloned XCTest repository. Make sure that it is located next to the `swift-corelibs-foundation` directory and has the name `swift-corelibs-xctest`.