compiler: separate package exports from entry roots

cmd/wcc/ww.h

@@ -589,7 +589,10 @@ struct Checker {
 	int	matcharms;	/* nesting count for yield */
 	int	errs;
 	int	is_test;	/* #15: `w6c -T` — collect @test fns + synth
-				 * the entry; loud-reject a user main. */
+					 * the entry; loud-reject a user main. */
+	int	is_test_package; /* package-test variant: validate/retain @test
+					 * bodies and export compiler-private metadata,
+					 * but do not synthesize an entry. */
 	const char *test_module;	/* generated dispatcher support qualifier */
 	int	sep_mode;	/* -c package compilation: imported interfaces are
 				 * present, so absent members are hard export errors. */