Native: switch to "Native" thread state for some Obj-C runtime calls

A lot of calls to Objective-C runtime are potentially blocking. This
commit adds a number of thread state switches to ensure these Obj-C
runtime calls happen in "Native" thread state.

Also, remove a bunch of such functions from CallsChecker exclude list.

kotlin-native/runtime/src/main/cpp/KString.cpp

@@ -135,6 +135,9 @@ void DisposeCString(char* cstring) {
 }
 
 ObjHeader* CreatePermanentStringFromCString(const char* nullTerminatedUTF8) {
+    // Note: this function can be called in "Native" thread state. But this is fine:
+    //   while it indeed manipulates Kotlin objects, it doesn't in fact access _Kotlin heap_,
+    //   because the accessed object is off-heap, imitating permanent static objects.
     const char* end = nullTerminatedUTF8 + strlen(nullTerminatedUTF8);
     size_t count = utf8::with_replacement::utf16_length(nullTerminatedUTF8, end);
     size_t headerSize = alignUp(sizeof(ArrayHeader), alignof(char16_t));

kotlin-native/runtime/src/main/cpp/ObjCExport.mm

@@ -121,6 +121,8 @@ extern "C" const TypeInfo* Kotlin_ObjCExport_getAssociatedTypeInfo(Class clazz)
 }
 
 static void setAssociatedTypeInfo(Class clazz, const TypeInfo* typeInfo) {
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   // Note: [NSValue valueWithPointer:] uses autorelease (without possibility to eliminate this at the call site),
   // so using alloc-init sequence to avoid this.
   NSValue* value = [[NSValue alloc] initWithBytes:&typeInfo objCType:@encode(void*)];
@@ -315,6 +317,8 @@ extern "C" void Kotlin_ObjCExport_initializeClass(Class clazz) {
     return;
   }
 
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   const TypeInfo* typeInfo = typeAdapter->kotlinTypeInfo;
   bool isClassForPackage = typeInfo == nullptr;
   if (!isClassForPackage) {
@@ -379,6 +383,8 @@ static void Kotlin_ObjCExport_initializeImpl() {
   RuntimeCheck(Kotlin_ObjCExport_toKotlinSelector != nullptr, "unexpected initialization order");
   RuntimeCheck(Kotlin_ObjCExport_releaseAsAssociatedObjectSelector != nullptr, "unexpected initialization order");
 
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   initTypeAdapters();
 
   SEL toKotlinSelector = Kotlin_ObjCExport_toKotlinSelector;
@@ -865,6 +871,8 @@ static void throwIfCantBeOverridden(Class clazz, const KotlinToObjCMethodAdapter
 }
 
 static const TypeInfo* createTypeInfo(Class clazz, const TypeInfo* superType, const TypeInfo* fieldsInfo) {
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   std_support::unordered_set<SEL> definedSelectors;
   addDefinedSelectors(clazz, definedSelectors);
 
@@ -1053,6 +1061,8 @@ static void addVirtualAdapters(Class clazz, const ObjCTypeAdapter* typeAdapter)
 static Class createClass(const TypeInfo* typeInfo, Class superClass) {
   RuntimeAssert(typeInfo->superType_ != nullptr, "");
 
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   int classIndex = (anonymousClassNextId++);
   std_support::string className = Kotlin_ObjCInterop_getUniquePrefix();
   className += "_kobjcc";

kotlin-native/runtime/src/main/cpp/ObjCInterop.mm

@@ -298,6 +298,8 @@ void* CreateKotlinObjCClass(const KotlinObjCClassInfo* info) {
     return createdClass;
   }
 
+  kotlin::NativeOrUnregisteredThreadGuard threadStateGuard(/* reentrant = */ true);
+
   Class newClass = allocateClass(info);
 
   RuntimeAssert(newClass != nullptr, "Failed to allocate Objective-C class");