Add PS4 port.

Thanks to Eddie Edwards.
Fix for -jdump docs.
Fix recording of BC_VARG.
Fix frame depth display for bytecode dump in -jdump.
Don't access dangling reference to reallocated IR.
DynASM: Emit version check after .arch directive.
Update changelog.
RELEASE LuaJIT-2.0.3
Fix compiler warnings.
x86/x64: Avoid use of SAHF instruction.
Fix check for reuse of SCEV results in FORL.
FFI: Fix pseudo type conversions for type punning.
FFI: Allow non-scalar cdata to be compared for equality by address.
Correct fix for reuse of SCEV results in FORL.
Fix top slot calculation for snapshots with continuations.
FFI: Fix cdata equality comparison against strings.
FFI: Fix cdata equality comparison against other Lua types.
Merge pull request #1 from agentzh/master

合并原作者更新