libroot: make API version available.

Change-Id: I370d5c8e9b4f076e7f115ca6c87bc7f943d36c17
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1850
Reviewed-by: Rene Gollent <[email protected]>

headers/private/libroot/libroot_private.h

@@ -19,6 +19,7 @@ extern "C" {
 #endif
 
 extern int __gABIVersion;
+extern int __gAPIVersion;
 
 extern char _single_threaded;
 	/* This determines if a process runs single threaded or not */

headers/private/runtime_loader/runtime_loader.h

@@ -57,6 +57,7 @@ struct rld_export {
 	const struct user_space_program_args *program_args;
 	const void* commpage_address;
 	int abi_version;
+	int api_version;
 };
 
 extern struct rld_export *__gRuntimeLoader;