fix: bytes test read one byte past the fixed map into the heap

rt.MW is the end of the fixed map (PW) since the growing heap landed; the
heap starts right there, so ld16(addr_b(rt.MW)-1) read the heap's first
byte: 0 on the default map by luck, 0x40 on the small map (16384).
Probe the real byte-op bound instead: core answers syscall(9,10) with the
host reservation MW; micro ports, whose bound is their memory size, fall
back to syscall(9,0).

0 files changed, 0 insertions, 0 deletions