* toplev.c (target_options): Add value field.

* toplev.c (target_options): Add value field.
(set_target_switch): Handle target options with	values.
* doc/tm.texi: Document how fixed vs variable target
options work.
* config/alpha/alpha.h, config/arc/arc.h, config/avr/avr.h,
config/c4x/c4x.h, config/cris/aout.h, config/cris/cris.h,
config/d30v/d30v.h, config/dsp16xx/dsp16xx.h,
config/frv/frv.h, config/i386/i386.h, config/ia64/ia64.h,
config/m32r/m32r.h, config/m68hc11/m68hc11.h,
config/m68k/m68k.h, config/m88k/m88k.h, config/mcore/mcore.h,
config/mips/mips.h, config/mmix/mmix.h, config/pa/pa.h,
config/rs6000/rs6000.h, config/rs6000/sysv4.h,
config/s390/s390.h, config/sparc/sparc.h, config/v850/v850.h:
Add value initializer to target options.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@65756 138bc75d-0d04-0410-961f-82ee72b054a4