extend.texi (AVR Built-in Functions): Update documentation of __builtin_avr_fmul*.

	* doc/extend.texi (AVR Built-in Functions): Update documentation
	of __builtin_avr_fmul*.
	* config/avr/avr.c (avr_init_builtins): Don't depend on
	AVR_HAVE_MUL.
	* config/avr/avr-c.c (avr_cpu_cpp_builtins): Ditto.
	* config/avr/avr.md (fmul): Rename to fmul_insn.
	(fmuls): Rename to fmuls_insn.
	(fmulsu): Rename to fmulsu_insn.
	(fmul,fmuls,fmulsu): New expander.
	(*fmul.call,*fmuls.call,*fmulsu.call): New Insn.
	* config/avr/t-avr (LIB1ASMFUNCS): Add _fmul, _fmuls, _fmulsu.
	* config/avr/libgcc.S (__fmul): New function.
	(__fmuls): New function.
	(__fmulsu,__fmulsu_exit): New function.

From-SVN: r175807