pub fn fold_string_builders(s: &mut Stmt, vt: &VarTable)Expand description
Fold new StringBuilder(...).append(x)...toString() chains into
StringConcat. Single-assignment temporaries carry the chain.
d8 drops append results (statement-form calls), so a builder whose chain
has STATEMENT appends attached is left alone: folding its toString
with only the ctor arguments would misstate the contents.