Function rlang_new_data_mask 

extern "C" fn rlang_new_data_mask(bottom: Sexp, _top: Sexp) -> Sexp

Create a new data mask from bottom and top environments.

Signature: SEXP rlang_new_data_mask_3.0.0(SEXP bottom, SEXP top)

Returns the bottom env as-is — a simplification that works for basic cases.