Merge #214

214: faster zeroing of .bss r=JOE1994 a=JOE1994

This PR updates the code for zeroing the .bss section.
The updated version uses `core::ptr::write_bytes()` which invokes a single **memset**,
compared to the current code which initializes one byte at a time.

The updated version would initialize the .bss section faster than the current version. 

Thank you for reviewing this PR :) :bowing_man: 

Co-authored-by: JOE1994 <joseph942010@gmail.com>