The new specs file generation introduces several problems.  This patch

- Fix build warnings

- Clean up unused code and the old, now dead specs definitions.

- Removes unused files and adjust build scripts / rules.

- Issues with avr-libc awareness:

-- Makes specs-generation aware of avr-libc (include tm.h in build script and 
depend on WITH_AVRLIBC).

-- avr-libc implements functions in libm.a which usually live in libgcc, hence 
add -lm to libgcc_spec, cf. PR54461.

-- The new libdev.a is a feature of avr-libc and not available with, e.g., 
newlib.  Hence remove it from lib_spec if the compiler is not configured for 
avr-libc (--with-avrlibc=no).

- Many minor issues with option propagation.

- -march had been added to multilib generation some time ago, but 
driver_self_spec was not aware of that option.


Ok for trunk?


BTW, anyone knows what -march= is good for?  It allows all kinds of silly 
option combinations like "-march=avrtiny -mmcu=atmega8" without any complaints.

What's wrong with -mmcu=avr* ? All architecture names start with "avr", and 
/no/ device name starts /with/ "avr", hence -mmcu= should be fine and work as 
smooth as in the last 10 years.

Why that -march= option?  If there is not a good reason for -march=, I'd 
propose to clean it up and use -mmcu=avr* instead.


Johann


gcc/
	Fix various problems with specs file generation.

	* config.gcc (extra_gcc_objs) [avr]: Remove.

	* config/avr/driver-avr.c: Remove file.
	* config/avr/t-avr (driver-avr.o): Remove rule.
	(gen-avr-mmcu-specs): Use CXX_FOR_BUILD, CXXFLAGS_FOR_BUILD and
	INCLUDES to build.  Depend on TM_H.
	* config/avr/gen-avr-mmcu-specs.c: Tidy up code.  Fix various
	build warnings.  Fix non-matching types and non-existing %-codes.
	(tm.h): Include.
	(*lib) [!WITH_AVRLIBC]: Don't link libdev.a.
	(*libgcc) [WITH_AVRLIBC]: Add "-lm".
	* config/avr/avrlibc.h (LIBGCC_SPEC): Remove definition.
	* config/avr/avr.h (DRIVER_SELF_SPECS): Fix handling of -march=.
	(CPP_SPEC, CC1PLUS_SPEC, ASM_SPEC, LINK_SPEC, LIB_SPEC)
	(LIBGCC_SPEC): Remove definitions.