Ignore a-b-a-linker-guard during cross-compilation

Author: Kobzol

Diff for: tests/run-make/a-b-a-linker-guard/rmake.rs

@@ -1,7 +1,8 @@
-// ignore-tidy-linelength
+// Test that if we build `b` against a version of `a` that has
+// one set of types, it will not run with a dylib that has a different set of types.
 
-// Test that if we build `b` against a version of `a` that has one set of types, it will not run
-// with a dylib that has a different set of types.
+//@ ignore-cross-compile
+// Reason: the compiled binary is executed
 
 use run_make_support::{run, run_fail, rustc};