Add stdbool header to libc
Add stdbool header to libc

Fixes failing compiler test 'btree.c', also useful thing to have

jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor