Add support for MSP430 silicon errata to the assembler.

Add support for MSP430 silicon errata to the assembler.

	* config/tc-msp430.c (PUSH_1X_WORKAROUND): Delete.
	(OPTION_SILICON_ERRATA): Define.
	(OPTION_SILICON_WARN): Define.
	(md_parse_opton): Handle silicon errata options.
	(md_longopts): Add silicon errata options.
	(ms_show_usage): Report silicon errata options.
	(msp430_srcoperand): Handle silicon errata.
	(msp430_operands): Likewise. Improve nop insertion.
	(msp430_fix_adjustable): Update warning generation.
	* doc/c-msp430.texi: Document silicon errata options.

tests	* gas/msp430/errata_fixes.s: New test source file.
	* gas/msp430/errata_fixes.d: New test control file.
	* gas/msp430/errata_warns.s: New test source file.
	* gas/msp430/errata_warns.d: New test control file.
	* gas/msp430/errata_warns.l: New test message file.
	* gas/msp430/msp430.exp: Run the new tests.
	* gas/msp430/bad.l: Update expected warning messages
	* gas/msp430/msp430.exp: Run the new tests.