ww: select build action from package declaration

test/tool/driver_test.ww

@@ -249,6 +249,7 @@ fn runrootargv(dir: str, root: str, name: str, drv: str,
 	let td: str = testenv.fresh();
 	let src: str = strings.concat(td, "/inline.ww");
 	testenv.writefile(src, strings.concat(
+		"package main;\n",
 		"package aa;\n",
 		"export fn getv() i32 = { return 7; };\n",
 		"package main;\n",

test/tool/rejects_test.ww

@@ -19,7 +19,7 @@ package rejects_test;
 // paramshadow (#19/#16) — value names and module names are disjoint:
 // a param/let/mlet/for-range/match-case binding named `shadowmod` in
 // a file importing module shadowmod is rejected at the decl site; the
-// renamed binding builds+runs 42 (no over-trigger); a param named
+// renamed binding in a real `package main` builds+runs 42 (no over-trigger); a param named
 // like a module a SIBLING module imports does not trip (src_imports
 // filters by the binding's own module — build+run exit 2). The
 // carrier's neg_selfimp leg is DROPPED here: