invoke.texi: Document --fix-cortex-m3.

invoke.texi: Document --fix-cortex-m3.

2008-11-13  Paul Brook  <paul@codesourcery.com>

	gcc/
	* doc/invoke.texi: Document --fix-cortex-m3.
	* config/arm/arm.c (arm_override_options): Set fix_cm3_ldrd if
	Cortex-M3 cpu is selected.
	(output_move_double): Avoid overlapping base register and first
	destination register when fix_cm3_ldrd.
	* config/arm/arm.opt: Add mfix-cortex-m3-ldrd.

From-SVN: r141822