Compute a better lint_node_id during expansion

When we need to emit a lint at a macro invocation, we currently use the
`NodeId` of its parent definition (e.g. the enclosing function). This
means that any `#[allow]` / `#[deny]` attributes placed 'closer' to the
macro (e.g. on an enclosing block or statement) will have no effect.

This commit computes a better `lint_node_id` in `InvocationCollector`.
When we visit/flat_map an AST node, we assign it a `NodeId` (earlier
than we normally would), and store than `NodeId` in current
`ExpansionData`. When we collect a macro invocation, the current
`lint_node_id` gets cloned along with our `ExpansionData`, allowing it
to be used if we need to emit a lint later on.

This improves the handling of `#[allow]` / `#[deny]` for
`SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` and some `asm!`-related lints.
The 'legacy derive helpers' lint retains its current behavior
(I've inlined the now-removed `lint_node_id` function), since
there isn't an `ExpansionData` readily available.

compiler/rustc_lint_defs/src/lib.rs

@@ -274,7 +274,7 @@ impl<HCX> ToStableHashKey<HCX> for LintId {
 }
 
 // Duplicated from rustc_session::config::ExternDepSpec to avoid cyclic dependency
-#[derive(PartialEq)]
+#[derive(PartialEq, Debug)]
 pub enum ExternDepSpec {
     Json(Json),
     Raw(String),
@@ -282,7 +282,7 @@ pub enum ExternDepSpec {
 
 // This could be a closure, but then implementing derive trait
 // becomes hacky (and it gets allocated).
-#[derive(PartialEq)]
+#[derive(PartialEq, Debug)]
 pub enum BuiltinLintDiagnostics {
     Normal,
     BareTraitObject(Span, /* is_global */ bool),