* c-common.c, c-common.h (dollars_in_ident): Remove.
	* c-opts.c (DOLLARS_IN_IDENTIFIERS): Default to true.
	(c_common_init_options, c_common_decode_option): Set dollars_in_ident.
	* cpphash.h (warned_dollar): Rename warn_dollars.
	* cppinit.c (struct lang_flags, lang_defaults, cpp_set_lang)
	Permit dollars regardless of -std=.
	(post_options): Set warn_dollars.
	* cpplex.c (forms_identifier_p): Use warn_dollars.
	* config/darwin.h, config/alpha/vms.h, config/m68hc11/m68hc11.h:
	Remove redundant definitions of DOLLARS_IN_IDENTIFIERS.
	* doc/cpp.texi, doc/cppopts.texi, doc/invoke.texi, doc/tm.texi:
	Update documentation.
testsuite:
	* gcc.dg/dollar.c: New test.

From-SVN: r66911