(parse_args): Add --no-warn, --warn, --fatal-warnings,
which become 'W', OPTION_WARN, and OPTION_WARN_FATAL.
(parse_args): Parse the new options.
(main): If there were warnings, and --fatal-warnings
was specified, print an error.
* as.h: New variable, flag_fatal_warnings, for new option.
* config/tc-sparc.c (md_longopts): Add --no-undeclared-regs option.
(sparc_ip): Warn if %g2 or %g3 register is used and not covered
by .register pseudo-op if -64 and --no-undeclared-regs.
(s_register, sparc_adjust_symtab): New functions.
* config/tc-sparc.h (tc_adjust_symtab, sparc_adjust_symtab):
Declare sparc_adjust_symtab as tc_adjust_symtab.
* doc/c-sparc.texi: Add description of #ignore special literal
for .register pseudo-op.
Move bitfield overflow checks to after the md_apply_fix call in
fixup_segment so that md_apply_fix has a chance to modify value.
Handle 8 and 16-bit pcrel relocs for i386.
Prototypes and other minor code cleanups.
