[Lightning] Updates for x86_64

[Paulo César Pereira de Andrade]

  Hi Paolo,

  I am adding a small set of patches, to setup the path, and make it
easier to review all steps, to get better x86_64 support, handling
varargs and/or extra arguments on stack, following the System V ABI
described in http://www.x86-64.org/documentation/abi.pdf

  Patch1 is a clear typo and should be trivial.

  Patch2 changes JIT_REXTMP to %r11, so that, when calling a function
with 6 integer arguments, it will not clobber the 6th argument in the
last moment, due to putting the function pointer on it.

  Patch3 defines symbolic names for extra SSE2 %xmmN registers, and
sets JIT_FPTMP to the topmost one.

  Patch4 increases JIT_V_NUM to 5, and make %r14 and %r15 available,
at the cost of needing to also save them. They are callee save registers
in the abi.

  Patch5 adds safety check on number of integer or float arguments
being passed to a function, and also increases the number of float
register arguments to 8. Also, it defines JIT_RA_NUM and JIT_FA_NUM
that matches the number of integer and float register arguments.

  Patch6 changes the default jit_extr_x_i to jit_extr_x_l for
jit_getarg_x, where x is either c, uc, s, us, and also changes
jit_getarg_{i,ui} to default to jit_movr_{l,ul}, so that it should
automatically work on 64 bits when arguments are passed on registers,
by properly sign extending, as arguments are already passed in 64 bits.

  Patch6 also changes the mapping of JIT_R(num) and JIT_V(num), as well
as JIT_REXTMP to use the 64 bits defines, so that it will not trigger
an JITFAIL on jit_getarg_l and jit_getarg_ul for example, due to _rC
telling it is a 32 bits registers. This is only an issue when
_ASM_SAFETY is defined.

  Patch6 is also the most intrusive one, so, I am sending more patches
after this one.

Thanks,
Paulo

0001-Correct-typo-in-fallback-jit_getarg_ul-for-arguments.patch
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0002-Change-JIT_REXTMP-to-r11-to-avoid-clobbering-6th-int.patch
Description: Text Data

0003-Define-extra-SSE2-xmmN-registers-and-set-JIT_FPTMP-t.patch
Description: Text Data

0004-Increase-JIT_V_NUM-to-5-and-add-save-restore-of-r14-.patch
Description: Text Data

0005-Add-safety-check-on-number-of-integer-and-float-argu.patch
Description: Text Data

0006-Change-jit_getarg_-c-uc-s-us-i-ui-to-extr_l-to-sign-.patch
Description: Text Data