Manually list proc macro exports

Author: Zoxc

src/librustc_codegen_ssa/back/linker.rs

@@ -376,10 +376,6 @@ impl<'a> Linker for GccLinker<'a> {
         // The object files have far more public symbols than we actually want to export,
         // so we hide them all here.
 
-        if crate_type == CrateType::ProcMacro {
-            return
-        }
-
         // Symbol visibility takes care of this for the WebAssembly.
         // Additionally the only known linker, LLD, doesn't support the script
         // arguments just yet