[TBDGen] The non-deallocating destructor applies to some @objc classes.

The non-deallocating destructor doesn't exists when dealloc can be overriden,
which means any class that inherits from a class defined in Objective-C. This
isn't necessarily all @objc classes, because of the
-disable-objc-attr-requires-foundation-module flag.

Fixes rdar://problem/40542246.

test/TBD/class_objc.swift.gyb

@@ -0,0 +1,37 @@
+// RUN: %empty-directory(%t)
+// RUN: %gyb %s > %t/main.swift
+
+// RUN: %target-swift-frontend -emit-ir -o- -parse-as-library -module-name test -import-objc-header %S/Inputs/objc_class_header.h -validate-tbd-against-ir=all %t/main.swift -disable-objc-attr-requires-foundation-module
+
+// RUN: %target-swift-frontend -enable-resilience -emit-ir -o- -parse-as-library -module-name test -import-objc-header %S/Inputs/objc_class_header.h -validate-tbd-against-ir=all %t/main.swift -disable-objc-attr-requires-foundation-module
+
+// REQUIRES: objc_interop
+
+import Foundation
+
+% names = ["Public", "Internal", "Private"]
+
+% for i, name in enumerate(names):
+% access = name.lower()
+
+// a class by itself
+${access} class ${name}Empty: NSObject {}
+
+// subclasses of that
+% for subname in names[i:]:
+% subaccess = subname.lower()
+${subaccess} class ${subname}Sub${name}Empty: ${name}Empty {}
+%end
+
+${access} class ${name}InheritObjCProtocol: NSObject, ObjCProtocol {}
+
+// some bugs were revealed when there's @objc without inheriting from
+// NSObject.
+@objc ${access} class ${name}ObjCOnly {}
+
+%end
+
+@usableFromInline
+@objc
+internal class InternalObjCOnlyUsableFromInline {}
+