Implement C++14 digit separators.

libcpp:

2013-10-31  Edward Smith-Rowland  <3dw4rd@verizon.net>

        Implement C++14 digit separators.
	* include/cpplib.h (cpp_options): Add digit_separators flag.
	* internal.h (DIGIT_SEP(c)): New macro.
	* expr.c (cpp_classify_number): Check improper placement of digit sep;
	(cpp_interpret_integer): Skip over digit separators.
	* init.c (lang_flags): Add digit_separators flag; (lang_defaults): Add
	digit separator flags per language; (cpp_set_lang): Set
	digit_separators
	* lex.c (lex_number): Add digits separator to allowable characters for
	C++14.


gcc/c-family:

2013-10-31  Edward Smith-Rowland  <3dw4rd@verizon.net>

        Implement C++14 digit separators.
	* c-lex.c (interpret_float): Remove digit separators from scratch string
	before building real literal.


gcc/testsuite:

2013-10-31  Edward Smith-Rowland  <3dw4rd@verizon.net>

        Implement C++14 digit separators.
	* g++.dg/cpp1y/digit-sep.C: New.
	* g++.dg/cpp1y/digit-sep-neg.C: New.
	* g++.dg/cpp1y/digit-sep-cxx11-neg.C: New.


libstdc++-v3:

2013-10-31  Edward Smith-Rowland  <3dw4rd@verizon.net>

        Implement C++14 digit separators.
	* include/include/bits/parse_numbers.h: Change struct _Digit<_Base, '`'>
	to struct _Digit<_Base, '\''>.

From-SVN: r204260