Update LuaJIT2 to 2.0.5.

LuaJIT 2.0.5 -- 2017-05-01

     * Add workaround for MSVC 2015 stdio changes.
     * Limit mcode alloc probing, depending on the available pool size.
     * Fix overly restrictive range calculation in mcode allocation.
     * Fix out-of-scope goto handling in parser.
     * Remove internal __mode = "K" and replace with safe check.
     * Add "proto" field to jit.util.funcinfo().
     * Fix GC step size calculation.
     * Initialize uv->immutable for upvalues of loaded chunks.
     * Fix for cdata vs. non-cdata arithmetics/comparisons.
     * Drop leftover regs in 'for' iterator assignment, too.
     * Fix PHI remarking in SINK pass.
     * Don't try to record outermost pcall() return to lower frame.
     * Add guard for obscure aliasing between open upvalues and SSA slots.
     * Remove assumption that lj_math_random_step() doesn't clobber FPRs.
     * Fix handling of non-numeric strings in arithmetic coercions.
     * Fix recording of select(n, ...) with off-trace varargs
     * Fix install for cross-builds.
     * Don't allocate unused 2nd result register in JIT compiler backend.
     * Drop marks from replayed instructions when sinking.
     * Fix unsinking check.
     * Properly handle OOM in trace_save().
     * Limit number of arguments given to io.lines() and fp:lines().
     * Fix narrowing of TOBIT.
     * OSX: Fix build with recent XCode.
     * x86/x64: Don't spill an explicit REF_BASE in the IR.
     * x86/x64: Fix instruction length decoder.
     * x86/x64: Search for exit jumps with instruction length decoder.
     * ARM: Fix BLX encoding for Thumb interworking calls.
     * MIPS: Don't use RID_GP as a scratch register.
     * MIPS: Fix emitted code for U32 to float conversion.
     * MIPS: Backport workaround for compact unwind tables.
     * MIPS: Fix cross-endian jit.bcsave.
     * MIPS: Fix BC_ISNEXT fallback path.
     * MIPS: Fix use of ffgccheck delay slots in interpreter.
     * FFI: Fix FOLD rules for int64_t comparisons.
     * FFI: Fix SPLIT pass for CONV i64.u64.
     * FFI: Fix ipairs() recording.
     * FFI: Don't propagate qualifiers into subtypes of complex.


(alnsn)