libgccjit: Add support for register variables [PR104072]

libgccjit: Add support for register variables [PR104072]

gcc/jit/
	PR jit/104072
	* docs/_build/texinfo/libgccjit.texi: Regenerate.
	* docs/topics/compatibility.rst (LIBGCCJIT_ABI_22): New ABI tag.
	* docs/topics/expressions.rst: Add documentation for the
	function gcc_jit_lvalue_set_register_name.
	* jit-playback.h: New function (set_register_name).
	* jit-recording.cc: New function (set_register_name) and add
	support for register variables.
	* jit-recording.h: New field (m_reg_name) and new function
	(set_register_name).
	* libgccjit.cc: New function (gcc_jit_lvalue_set_register_name).
	* libgccjit.h: New function (gcc_jit_lvalue_set_register_name).
	* libgccjit.map (LIBGCCJIT_ABI_22): New ABI tag.

gcc/
	PR jit/104072
	* reginfo.cc: New functions (clear_global_regs_cache,
	reginfo_cc_finalize) to avoid an issue where compiling the same
	code multiple times gives an error about assigning the same
	register to 2 global variables.
	* rtl.h: New function (reginfo_cc_finalize).
	* toplev.cc: Call it.

gcc/testsuite/
	PR jit/104072
	* jit.dg/all-non-failing-tests.h: Add new
	test-register-variable.
	* jit.dg/harness.h: Add -fdiagnostics-color=never to context's
	command-line options.
	* jit.dg/test-error-register-variable-bad-name.c: New test.
	* jit.dg/test-error-register-variable-size-mismatch.c: New test.
	* jit.dg/test-register-variable.c: New test.