Use a staticlib instead of a dylib for utf8 test

On OS X the linker doesn't like producing a dylib with undefined
symbols.

Author: wthrowe

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

@@ -8,5 +8,5 @@ bad_dir := $(TMPDIR)/zzz$$'\xff'
 all:
 	$(RUSTC) library.rs
 	mkdir $(bad_dir)
-	mv $(call DYLIB,library) $(bad_dir)
+	mv $(call STATICLIB,library) $(bad_dir)
 	LIBRARY_PATH=$(bad_dir) $(RUSTC) exec.rs 2>&1 | grep this_symbol_not_defined

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

@@ -8,12 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![crate_type = "dylib"]
+#![crate_type = "staticlib"]
 
 extern "C" {
     fn this_symbol_not_defined();
 }
 
+#[no_mangle]
 pub extern "C" fn foo() {
     unsafe { this_symbol_not_defined(); }
 }