[tests] Make test runners exit with errorlevel 1 if a test fails.

tests/core/hash/test_core_hash.odin

@@ -5,6 +5,7 @@ import "core:hash"
 import "core:time"
 import "core:testing"
 import "core:fmt"
+import "core:os"
 
 TEST_count := 0
 TEST_fail  := 0
@@ -35,6 +36,9 @@ main :: proc() {
 	test_xxhash_vectors(&t)
 	test_crc64_vectors(&t)
 	fmt.printf("%v/%v tests successful.\n", TEST_count - TEST_fail, TEST_count)
+	if TEST_fail > 0 {
+		os.exit(1)
+	}
 }
 
 /*