Get tests passing again

`T` no longer has a writer assigned to it.

`test_core_cbor.odin` has global state and is run with `odin test`,
so I've set it to use only one thread.

tests/core/compress/test_core_compress.odin

@@ -21,7 +21,7 @@ import "core:fmt"
 
 import "core:mem"
 import "core:os"
-import "core:io"
+// import "core:io"
 
 TEST_count := 0
 TEST_fail  := 0
@@ -45,8 +45,8 @@ when ODIN_TEST {
 }
 
 main :: proc() {
-	w := io.to_writer(os.stream_from_handle(os.stdout))
-	t := testing.T{w=w}
+	// w := io.to_writer(os.stream_from_handle(os.stdout))
+	t := testing.T{}//{w=w}
 	zlib_test(&t)
 	gzip_test(&t)
 	shoco_test(&t)
@@ -195,4 +195,4 @@ shoco_test :: proc(t: ^testing.T) {
 		size, err = shoco.decompress(v.compressed[:v.short_sentinel], buffer[:])
 		expect(t, err == .Stream_Too_Short, "Expected `decompress` to return `Stream_Too_Short` because there was no more data after non-ASCII sentinel.")
 	}
-}
+}