Document long-form command-line options [PR122243]

Document long-form command-line options [PR122243]

GCC has long supported long-form command-line options with the same
meanings as its traditional one-character options, e.g. --output as an
alias for -o, --language for -x, and so on.  However, these have never
been documented in the manual.  This patch adds the missing
documentation for these options, plus some additional options that
have previously undocumented two-dash aliases with the same names as
the one-dash form (e.g., -dumpdir and --dumpdir).

gcc/ChangeLog
	PR other/122243
	* doc/cppdiropts.texi: Document --include-directory,
	--include-directory-after, --include-barrier, --include-prefix,
	--include-with-prefix, --include-with-prefix-after,
	--include-with-prefix-before, --no-standard-includes.
	--embed-directory.
	* doc/cppopts.texi: Document --define-macro, --undefine-macro,
	--include, --imacros, --dependencies, --user-dependencies,
	--print-missing-file-dependencies, --write-dependencies,
	--write-user-dependencies, --comments, --comments-in-macros,
	--no-line-commands, --traditional, --traditional-cpp,
	--trigraphs, --trace-includes, --dump.
	* doc/invoke.texi: Add missing long options to Option Summary.
	Document --language, --compile, --assemble, --preprocess,
	--output, --dumpbase, --dumpbase-ext, --dumpdir,
	--verbose, --pass-exit-codes, --pipe, --specs, --ansi,
	--no-warnings, --pedantic, --pedantic-errors, --all-warnings,
	--extra-warnings, --debug, --optimize, --profile, -coverage,
	--no-integrated-cpp, --for-assembler, --no-standard-libraries,
	--entries, --pie, --static-pie, --static, --shared, --symbolic,
	--for-linker, --force-link, --library-directory, --prefix,
	--no-canonical-prefixes, --dump, --save-temps, --print-file-name,
	--print-multi-directory, --print-multi-lib,
	--print-multi-os-directory, --print-multiarch,
	--print-prog-name, --print-libgcc-file-name, --print-search-dirs,
	--print-sysroot, --print-sysroot-headers-suffix.