Clearing array with setting length to 0 replaced with [] for being short
and marginally efficient. For reference: [] is turned into a sequence of
around 15 machine instructions on x64 (if bump pointer allocation succeeds),
whereas a.length=0 is a C++ runtime function call, which requires 10-100x as
many instructions.
Benedikt Meurer
PR Close#20395
swseverance
Anuj Jain
Shavi Pathania
Jesus Rodriguez
Peter Bacon Darwin