Rollup merge of #105343 - nbdd0121:hir, r=fee1-dead

Simplify attribute handling in rustc_ast_lowering

Given that attributes is stored in a separate BTreeMap, it's not necessary to pass it in when constructing `hir::Expr`. We can just construct `hir::Expr` and then call `self.lower_attrs` later if it needs attributes.

As most desugaring code don't use attributes, this allows some code cleanup.

diff --cc compiler/rustc_ast_lowering/src/expr.rs
Simple merge