syntax_data: {"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let new_block = BasicBlockData::new_stmts(
context_before:     // Drain every statement after this one and move the current terminator to a new basic block.
context_after:         block_data.statements.split_off(location.statement_index),