Add a regression test for #29122 (fixed in #29134)

src/test/run-make/linker-output-non-utf8/Makefile

@@ -0,0 +1,24 @@
+-include ../tools.mk
+
+# Make sure we don't ICE if the linker prints a non-UTF-8 error message.
+
+ifdef IS_WINDOWS
+# ignore windows
+
+# This does not work in its current form on windows, possibly due to
+# gcc bugs or something about valid Windows paths.  See issue #29151
+# for more information.
+all:
+
+else
+
+# The zzz it to allow humans to tab complete or glob this thing.
+bad_dir := $(TMPDIR)/zzz$$'\xff'
+
+all:
+	$(RUSTC) library.rs
+	mkdir $(bad_dir)
+	mv $(TMPDIR)/liblibrary.a $(bad_dir)
+	LIBRARY_PATH=$(bad_dir) $(RUSTC) exec.rs 2>&1 | grep this_symbol_not_defined
+
+endif

src/test/run-make/linker-output-non-utf8/exec.rs

@@ -0,0 +1,16 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[link(name="library")]
+extern "C" {
+    fn foo();
+}
+
+fn main() { unsafe { foo(); } }

src/test/run-make/linker-output-non-utf8/library.rs

@@ -0,0 +1,20 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "staticlib"]
+
+extern "C" {
+    fn this_symbol_not_defined();
+}
+
+#[no_mangle]
+pub extern "C" fn foo() {
+    unsafe { this_symbol_not_defined(); }
+}