Squashed 'luajit/' changes from 2be62dc..80efb07

80efb07 DynASM: Emit version check after .arch directive.
416abff Don't access dangling reference to reallocated IR.
e941508 Fix frame depth display for bytecode dump in -jdump.
ef3cc47 Fix recording of BC_VARG.
900d0ce Fix for -jdump docs.
6a47e12 Add PS4 port.
998651f Don't purge modified function from stack slots in BC_RET.
1994a24 FFI: Disallow nested VLS.
2bc63bb Prevent BASE register coalescing if parent uses IR_RETF.
e3d5b21 Fix quoting in xedkbuild.bat (again).

git-subtree-dir: luajit
git-subtree-split: 80efb077500ca368b26aab0aadcc4e2e877b10ab
Merge commit '7ace682bb34f855306826448c1f19dc5866a3d12'