Update doc comment

Author: elsh

include/swift/AST/Decl.h

@@ -2973,7 +2973,8 @@ class ValueDecl : public Decl {
   /// \c \@usableFromInline, \c \@inlinalbe, and \c \@_alwaysEmitIntoClient
   bool isUsableFromInline() const;
 
-  /// Allows skipping type check if the following conditions are met:
+  /// Treat as public and allow skipping type check if the following conditions
+  /// are met:
   /// - This decl has a package access level.
   /// - Has a @usableFromInline (or other inlinable) attribute
   /// - And is defined in a module built from a public or private