Add locale.h in libc-test
diff --git a/libc-test/build.rs b/libc-test/build.rs
index 6475db5..0f9c10c 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -38,6 +38,7 @@
     cfg.header("errno.h")
        .header("fcntl.h")
        .header("limits.h")
+       .header("locale.h")
        .header("stddef.h")
        .header("stdint.h")
        .header("stdio.h")