Disable gdb pretty printer global section on wasm targets

The wasm targets don't support gdb anyway so there's no need for this
section there.

src/librustc_target/spec/wasm32_base.rs

@@ -140,6 +140,9 @@ pub fn options() -> TargetOptions {
         has_elf_tls: true,
         tls_model: "local-exec".to_string(),
 
+        // gdb scripts don't work on wasm blobs
+        emit_debug_gdb_scripts: false,
+
         .. Default::default()
     }
 }