The 0-arg ltrim/rtrim/trim used to return input unchanged. Hare's
0-arg form strips [' ', '\n', '\t', '\r'] (ref/hare/strings/trim.ha:6).
Aligned by delegating to bytes.ltrim/bytes.rtrim with the whitespace
set spread inline at the call site — the obvious `let ws = whitespace[0:4]`
shape produces a slice whose ptr does NOT alias storage (#40).
N-arg forms (strip-specific-runes) untouched.
Test rows retargeted to Hare's canonical inputs from trim.ha:78/85
so '\r' is exercised alongside ' '/'\t'/'\n'.
Hojun-Cho
18fe1a7a31