invoke.texi: Rename MIPS's -mfix-vr4122-bugs to -mfix-vr4120.

invoke.texi: Rename MIPS's -mfix-vr4122-bugs to -mfix-vr4120.

	* doc/invoke.texi: Rename MIPS's -mfix-vr4122-bugs to -mfix-vr4120.
	* config/mips/mips.h (MASK_FIX_VR4120): Renamed from MASK_FIX_VR4122.
	(TARGET_FIX_VR4120): Likewise TARGET_FIX_VR4122.
	(TARGET_SWITCHES): Replace -mfix-vr4122-bugs with -mfix-vr4120.
	(ASM_SPEC): Update accordingly.
	* config/mips/mips.c: Update after above renaming.
	* config/mips/mips.md, config/mips/t-vr, config/mips/vr.h: Likewise.
	* config/mips/vr4120-div.S: Renamed from vr4122-div.S.

From-SVN: r80679