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/test/codegen/gdb_debug_script_load.rs

@@ -1,6 +1,8 @@
 // ignore-tidy-linelength
 // ignore-windows
 // ignore-macos
+// ignore-wasm
+// ignore-emscripten
 
 // compile-flags: -g -C no-prepopulate-passes