ww: lib tests run via -T test mode; bare mains retired (closes @test conversion)

'ww test' gains the istest build path (-T injection in build_one/
buildone) and do_test/dotest accept -I, mirroring do_run - both twins.
The 35 converted lib tests drop their interim bare mains (-T
synthesizes the entry from @test fns and rejects a user main); their
35 C run-drivers flip 'ww run' -> 'ww test'; 989_lib_byteid compiles
lib tests under -T (8 user-main probe fixtures stay non-T, gated on
the fixture field). Abort-on-first-failure stands until the deferred
record-and-continue harness lands with the multi-package arc.

lib/fnmatch/fnmatchtest.ww

@@ -247,15 +247,3 @@ fn check(pat: str, s: str, expected: bool, flags: i32) void = {
 	let nesc: i32 = 2;		// NOESCAPE
 	check("a\\*.c",      "a*.c",   false, nesc);
 };
-
-export fn main() i32 = {
-	basic();
-	brackets();
-	ctype();
-	period();
-	noescape();
-	musl_basic();
-	pathname();
-	combined();
-	return 0;
-};