Avoid mangle_name_by_type_only call in tydesc names unless debugging.

Author: graydon

src/comp/middle/trans.rs

@@ -1783,7 +1783,14 @@ fn declare_tydesc(@local_ctxt cx, ty.t t) -> @tydesc_info {
 
     auto glue_fn_ty = T_ptr(T_glue_fn(ccx.tn));
 
-    auto name = mangle_name_by_type_only(ccx, t, "tydesc");
+    auto name;
+    if (cx.ccx.sess.get_opts().debuginfo) {
+        name = mangle_name_by_type_only(cx.ccx, t, "tydesc");
+        name = sanitize(name);
+    } else {
+        name = mangle_name_by_seq(cx.ccx, cx.path, "tydesc");
+    }
+
     auto gvar = llvm.LLVMAddGlobal(ccx.llmod, T_tydesc(ccx.tn),
                                    Str.buf(name));
     auto tydesc = C_struct(vec(C_null(T_ptr(T_ptr(T_tydesc(ccx.tn)))),