* lightening.h:
* lightening/lightening.c (jit_begin_data): Add max data size
parameter. If nonzero, can allow the JIT to avoid prematurely
emitting a constant pool.
(jit_end_data): Allow pending literals.
* tests/jmp_table.c (run_test): Use new API.
* lightening.h:
* lightening/lightening.c (jit_begin_data, jit_end_data)
(jit_emit_u8, jit_emit_u16, jit_emit_u32, jit_emit_u64): Add new raw
data-emitting primitives, bracketed by begin/end so that we can flush
constant pools first, if needed.
* lightening/lightening.c (struct jit_state): Add new emitting_data
flag.
(jit_begin, jit_reset, jit_end): Handle the new flag.
(emit_abs_reloc): Move here, from x86.c.
* lightening/x86.c (emit_abs_reloc): Remove.
(jit_try_shorten): Don't shorten if loc == start; could be raw data.
* tests/jmp_table.c: New test.
