syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                 if lhs_expr.ty.needs_drop(this.tcx, this.typing_env()) {
context_before:                 // dropped.
context_after:                     let rhs = unpack!(block = this.as_local_rvalue(block, rhs));