transpile: remove invalid Punct::new(' ') in fn convert_asm

`' '` is not a valid punctuation, and newer versions of `proc_macro2` don't allow it.
However, we don't seem to need the space here at all,
as `zstd` (from `c2rust-testsuite`) still transpiles and compiles successfully without it.

This also updates to `proc-macro` `1.0.95` (from `1.0.86`) to test this.

Author: kkysen

Cargo.lock

@@ -966,7 +966,6 @@ impl<'c> Translation<'c> {
             tokens.push(TokenTree::Punct(Punct::new(',', Alone)));
             let result = mk().call_expr(mk().ident_expr("out"), vec![mk().lit_expr(clobber)]);
             push_expr(&mut tokens, result);
-            tokens.push(TokenTree::Punct(Punct::new(' ', Alone)));
             push_expr(&mut tokens, mk().ident_expr("_"));
         }