GNU Lightning 2.2.1 release

[Paulo César Pereira de Andrade]

GNU lightning 2.2.1 released!

GNU lightning is a library to aid in making portable programs
that compile assembly code at run time.

Development:
http://git.savannah.gnu.org/cgit/lightning.git

Download release:
ftp://ftp.gnu.org/gnu/lightning/lightning-2.2.1.tar.gz

  GNU Lightning 2.2.1 main new features:

o Variable stack framesize implemented for aarch64, arm, i686, mips,
  riscv, loongarch and x86_64. This means function calls use only
  the minimum required stack space for prolog and epilog.
o Optimization of prolog and epilog to not create a frame pointer if
  not required, and not even save and restore the stack pointer if
  not required on a leaf function. These features implemented for the
  ports with variable stack framesize.
o New clor, czr, ctor and ctzr instructions, that count leading/trailing
  zeros/ones. These use hardware implementation when available, otherwise
  fallback to a software implementation.
o Correct several bugs with jit_arg_register_p and jit_putarg{r,i}{_f,_d}.
  These bugs were not noticed earlier due to an incorrect check for
  correctness in check/carg.c.
o Add rip relative addressing support for x86_64 and shorter signed 64
  bit constant load if the constant fits in a signed 32 bit integer.
  This significantly reduces code size generation.
o Correct bugs in branch generation code for pppc and sparc.
o Correct bug in signed 32 bit integer load in ppc 64 bits.
o Add short relative unconditional branches and calls to mips, reducing
  code size generation.
o And several extra minor optimizations.