tests: ignore wasm32 for run-pass/proc-macro/expand-with-a-macro.

Author: eddyb

src/test/run-pass/proc-macro/expand-with-a-macro.rs

@@ -10,6 +10,8 @@
 
 // aux-build:expand-with-a-macro.rs
 
+// ignore-wasm32-bare compiled with panic=abort by default
+
 #![deny(warnings)]
 
 #[macro_use]