Rollup merge of #110823 - compiler-errors:tweak-await-span, r=b-naber

Tweak await span to not contain dot

Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.

Fixes #110761

This mostly touches a bunch of tests to tighten their `await` span.

compiler/rustc_ast/src/ast.rs

@@ -1430,8 +1430,8 @@ pub enum ExprKind {
     /// The async block used to have a `NodeId`, which was removed in favor of
     /// using the parent `NodeId` of the parent `Expr`.
     Async(CaptureBy, P<Block>),
-    /// An await expression (`my_future.await`).
-    Await(P<Expr>),
+    /// An await expression (`my_future.await`). Span is of await keyword.
+    Await(P<Expr>, Span),
 
     /// A try block (`try { ... }`).
     TryBlock(P<Block>),