runtime: add and switch to SWIFT_NOINLINE (NFC)

This switches the `LLVM_ATTRIBUTE_NOINLINE` to a local copy which is
namespaced in Swift.

stdlib/public/SwiftShims/RefCount.h

@@ -182,8 +182,8 @@ namespace swift {
 }
 
 // FIXME: HACK: copied from HeapObject.cpp
-extern "C" SWIFT_LIBRARY_VISIBILITY LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-void _swift_release_dealloc(swift::HeapObject *object);
+extern "C" SWIFT_LIBRARY_VISIBILITY SWIFT_NOINLINE LLVM_ATTRIBUTE_USED void
+_swift_release_dealloc(swift::HeapObject *object);
 
 namespace swift {
 
@@ -697,19 +697,19 @@ class RefCounts {
 
   // Out-of-line slow paths.
 
-  LLVM_ATTRIBUTE_NOINLINE
+  SWIFT_NOINLINE
   void incrementSlow(RefCountBits oldbits, uint32_t inc) SWIFT_CC(PreserveMost);
 
-  LLVM_ATTRIBUTE_NOINLINE
+  SWIFT_NOINLINE
   void incrementNonAtomicSlow(RefCountBits oldbits, uint32_t inc);
 
-  LLVM_ATTRIBUTE_NOINLINE
+  SWIFT_NOINLINE
   bool tryIncrementSlow(RefCountBits oldbits);
 
-  LLVM_ATTRIBUTE_NOINLINE
+  SWIFT_NOINLINE
   bool tryIncrementNonAtomicSlow(RefCountBits oldbits);
 
-  LLVM_ATTRIBUTE_NOINLINE
+  SWIFT_NOINLINE
   void incrementUnownedSlow(uint32_t inc);
 
   public:

stdlib/public/SwiftShims/Visibility.h

@@ -66,6 +66,12 @@
 #define SWIFT_ALWAYS_INLINE
 #endif
 
+#if __has_attribute(noinline)
+#define SWIFT_NOINLINE __attribute__((__noinline__))
+#else
+#define SWIFT_NOINLINE
+#endif
+
 #if __has_attribute(unavailable)
 #define SWIFT_ATTRIBUTE_UNAVAILABLE __attribute__((__unavailable__))
 #else

stdlib/public/runtime/Casting.cpp

@@ -248,9 +248,7 @@ swift::swift_getMangledTypeName(const Metadata *type) {
 // This is noinline to preserve this frame in stack traces.
 // We want "dynamicCastFailure" to appear in crash logs even we crash 
 // during the diagnostic because some Metadata is invalid.
-LLVM_ATTRIBUTE_NORETURN
-LLVM_ATTRIBUTE_NOINLINE
-void 
+LLVM_ATTRIBUTE_NORETURN SWIFT_NOINLINE void
 swift::swift_dynamicCastFailure(const void *sourceType, const char *sourceName,
                                 const void *targetType, const char *targetName,
                                 const char *message) {

stdlib/public/runtime/Errors.cpp

@@ -224,7 +224,7 @@ static _Unwind_Reason_Code SwiftUnwindFrame(struct _Unwind_Context *context, voi
 }
 #endif
 
-LLVM_ATTRIBUTE_NOINLINE
+SWIFT_NOINLINE
 void swift::printCurrentBacktrace(unsigned framesToSkip) {
 #if SWIFT_SUPPORTS_BACKTRACE_REPORTING
   constexpr unsigned maxSupportedStackDepth = 128;
@@ -320,8 +320,8 @@ reportNow(uint32_t flags, const char *message)
 #endif
 }
 
-LLVM_ATTRIBUTE_NOINLINE SWIFT_RUNTIME_EXPORT
-void _swift_runtime_on_report(uintptr_t flags, const char *message,
+SWIFT_NOINLINE SWIFT_RUNTIME_EXPORT void
+_swift_runtime_on_report(uintptr_t flags, const char *message,
                          RuntimeErrorDetails *details) {
   // Do nothing. This function is meant to be used by the debugger.
 

stdlib/public/runtime/HeapObject.cpp

@@ -327,8 +327,8 @@ HeapObject *swift::swift_allocEmptyBox() {
 }
 
 // Forward-declare this, but define it after swift_release.
-extern "C" SWIFT_LIBRARY_VISIBILITY LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-void _swift_release_dealloc(HeapObject *object);
+extern "C" SWIFT_LIBRARY_VISIBILITY SWIFT_NOINLINE LLVM_ATTRIBUTE_USED void
+_swift_release_dealloc(HeapObject *object);
 
 static HeapObject *_swift_retain_(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_retain);

stdlib/public/runtime/Leaks.h

@@ -30,14 +30,19 @@ namespace swift {
 struct HeapObject;
 }
 
-SWIFT_CC(swift) SWIFT_RUNTIME_EXPORT LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
+SWIFT_CC(swift)
+SWIFT_RUNTIME_EXPORT SWIFT_NOINLINE LLVM_ATTRIBUTE_USED
 void _swift_leaks_startTrackingObjects(const char *);
-SWIFT_CC(swift) SWIFT_RUNTIME_EXPORT LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
+
+SWIFT_CC(swift)
+SWIFT_RUNTIME_EXPORT SWIFT_NOINLINE LLVM_ATTRIBUTE_USED
 int _swift_leaks_stopTrackingObjects(const char *);
-SWIFT_RUNTIME_EXPORT LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-void _swift_leaks_startTrackingObject(swift::HeapObject *);
-SWIFT_RUNTIME_EXPORT LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-void _swift_leaks_stopTrackingObject(swift::HeapObject *);
+
+SWIFT_RUNTIME_EXPORT SWIFT_NOINLINE LLVM_ATTRIBUTE_USED void
+_swift_leaks_startTrackingObject(swift::HeapObject *);
+
+SWIFT_RUNTIME_EXPORT SWIFT_NOINLINE LLVM_ATTRIBUTE_USED void
+_swift_leaks_stopTrackingObject(swift::HeapObject *);
 
 #define SWIFT_LEAKS_START_TRACKING_OBJECT(obj)                                 \
   _swift_leaks_startTrackingObject(obj)