Fix regression caused by M2libc's fb6701a73189afca152ea1154650c315df4e6a93 commit
Set OPERATING_SYSTEM=Linux environmental variable.
Add M2libc/stdio.h to build sources.
Fix a missing quotation mark.
Breaking change in M2libc v0.2.1
Set TMPDIR for systems without /tmp
This also needs some adjustment to build scripts.
fcntl.h has to be built before stdlib.c.
riscv32: add kaem scripts.
Clean up the bits that were not adjusted following live-bootstrap
Move kaem.aarch64 to top directory for better live-bootstrap integration
convert AArch64 hex2 to use stack for read/write syscalls to speed up qemu performance
Move kaem.x86 to top directory for better live-bootstrap integration
Put all build artifacts in artifact and isolate the riscv64 build and output