Declare librustrt a static dependency of libextra

This wasn't uncovered during testing because the librustrt is available locally
in the build directory (and it needs to be for all the tests to link against it
as well).

Closes #10765

diff --git a/src/libextra/flate.rs b/src/libextra/flate.rs
index a4a10ccfa73fa98067cf752ddc792750cf38b01d..5ebbbb2bbd61c5150a7828360bd66d0d201e7f2a 100644 (file)
--- a/src/libextra/flate.rs
+++ b/src/libextra/flate.rs
@@ -23,7 +23,7 @@
 pub mod rustrt {
     use std::libc::{c_int, c_void, size_t};
 
-    #[link(name = "rustrt")]
+    #[link(name = "rustrt", kind = "static")]
     extern {
         pub fn tdefl_compress_mem_to_heap(psrc_buf: *c_void,
                                           src_buf_len: size_t,