Rollup merge of #138063 - compiler-errors:improve-attr-unpretty, r=jdonszelmann

Improve `-Zunpretty=hir` for parsed attrs

0. Rename `print_something` to `should_render` to make it distinct from `print_attribute` in that it doesn't print anything, it's just a way to probe if a type renders anything.
1. Fixes a few bugs in the `PrintAttribute` derive. Namely, the `__printed_anything` variable was entangled with the `should_render` call, leading us to always render field names but never render commas.
2. Remove the outermost `""` from the attr.
3. Debug print `Symbol`s. I know that this is redundant for some parsed attributes, but there's no good way to distinguish symbols that are ident-like and symbols which are cooked string literals. We could perhaps *conditionally* to fall back to a debug printing if the symbol doesn't match an ident? But seems like overkill.

Based on #138060, only review the commits not in that one.

compiler/rustc_hir_pretty/src/lib.rs

@@ -118,9 +118,9 @@ impl<'a> State<'a> {
                 self.hardbreak()
             }
             hir::Attribute::Parsed(pa) => {
-                self.word("#[attr=\"");
+                self.word("#[attr = ");
                 pa.print_attribute(self);
-                self.word("\")]");
+                self.word("]");
                 self.hardbreak()
             }
         }