re PR target/54222 ([avr] Implement fixed-point support)

gcc/
	PR target/54222
	* config/avr/avr-dimode.md (umulsidi3, mulsidi3): New expanders.
	(umulsidi3_insn, mulsidi3_insn): New insns.

libgcc/
	PR target/54222
	* config/avr/t-avr (LIB2FUNCS_EXCLUDE): Add: _usmulUHA, _usmulUSA,
	_ssmulHA, _ssmulSA.
	(LIB1ASMFUNCS): Add: _muldi3_6, _mulsidi3, _umulsidi3, _usmuluha3,
	_ssmulha3, _usmulusa3, _ssmulsa3.
	* config/avr/lib1funcs.S (__muldi3_6): Break out of __muldi3.
	(__muldi3): XCALL __muldi3_6 instead of rcall.
	(__umulsidi3, __mulsidi3): New functions.
	(do_prologue_saves, do_epilogue_restores): New .macros.
	(__divdi3_moddi3): Use them.
	* config/avr/lib1funcs-fixed.S (__usmuluha3, __ssmulha3)
	(__usmulusa3, __ssmulsa3): New functions.

From-SVN: r195978