expmed.c (extract_fixed_bit_field): Remove unused code.

	* expmed.c (extract_fixed_bit_field): Remove unused code.
	* system.h: Poison SLOW_ZERO_EXTEND.
	* doc/tm.texi: Remove.
	* config/1750a/1750a.h (SLOW_ZERO_EXTEND): Remove.
	* config/arm/arm.h: Likewise.
	* config/avr/avr.h: Likewise.
	* config/clipper/clipper.h: Likewise.
	* config/convex/convex.h: Likewise.
	* config/d30v/d30v.h: Likewise.
	* config/dsp16xx/dsp16xx.h: Likewise.
	* config/elxsi/elxsi.h: Likewise.
	* config/fr30/fr30.h: Likewise.
	* config/h8300/h8300.h: Likewise.
	* config/i370/i370.h: Likewise.
	* config/i386/i386.h: Likewise.
	* config/m68k/m68k.h: Likewise.
	* config/mips/mips.h: Likewise.
	* config/ns32k/ns32k.h: Likewise.
	* config/pdp11/pdp11.h: Likewise.
	* config/pj/pj.h: Likewise.
	* config/s390/s390.h: Likewise.
	* config/sh/sh.h: Likewise.
	* config/stormy16/stormy16.h: Likewise.
	* config/v850/v850.h: Likewise.
	* config/vax/vax.h: Likewise.
	* config/we32k/we32k.h: Likewise.

From-SVN: r48893