Add command support for Guile.

	* Makefile.in (SUBDIR_GUILE_OBS): Add scm-cmd.o.
	(SUBDIR_GUILE_SRCS): Add scm-cmd.c.
	(scm-cmd.o): New rule.
	* guile/guile-internal.h (gdbscm_gc_xstrdup): Declare.
	(gdbscm_user_error_p): Declare.
	(gdbscm_parse_command_name): Declare.
	(gdbscm_valid_command_class_p): Declare.
	(gdbscm_initialize_commands): Declare.
	* guile/guile.c (initialize_gdb_module): Call
	gdbscm_initialize_commands.
	* guile/lib/gdb.scm: Export command symbols.
	* guile/lib/gdb/init.scm (%exception-keys): Add gdb:user-error.
	(throw-user-error): New function.
	* guile/scm-cmd.c: New file.
	* guile/scm-exception.c (user_error_symbol): New static global.
	(gdbscm_user_error_p): New function.
	(gdbscm_initialize_exceptions): Set user_error_symbol.
	* scm-utils.c (gdbscm_gc_xstrdup): New function.

	testsuite/
	* gdb.guile/scm-cmd.c: New file.
	* gdb.guile/scm-cmd.exp: New file.

	doc/
	* guile.texi (Guile API): Add entry for Commands In Guile.
	(Basic Guile) <parse-and-eval>: Add reference.
	(Basic Guile) <string->argv>: Move definition to Commands In Guile.
	(GDB Scheme Data Types): Mention <gdb:command> object.
	(Commands In Guile): New node.
 If the binutils testsuite is run on an installed toolchain the tests involving
the bfdtest1 and bfdtest2 executables will fail because they are not installed.
 Since the programs only exist to be used by the testsuite it does not make sense
to install them, so instead I have chosen to create a patch which skips the tests
when they are not present.

	* binutils-all/ar.exp: Skip tests involving bfdtest1 and bfdtest2
	if these executables are not present.
Change -mz command line option to -my for the MSP430 port of GAS.

	* config/tc-msp430.c (OPTION_WARN_INTR_NOPS): Use y instead of z.
	(OPTION_NO_WARN_INTR_NOPS): Use Y instead of Z.
	* doc/c-msp430.texi: Update command line option description.

	* gas/msp430/bad.d: Use -my not -mz.
Fix the disassembly of MSP430 extended index addressing mode.

	* msp430-dis.c (msp430_doubleoperand): Use extension_word to
	decide when extended addressing is being used.
Fix a small but in the emulation of the MSP430 hardware multiply.

	* msp430-sim.c (get_op): Handle reads of low result register when
	in MAC mode.
	(put_op): Copy MAC result into result words.
	Handle writes to the low result register.