Sync libiberty with upstream GCC.

Sync libiberty with upstream GCC.

libiberty/ChangeLog:

	* d-demangle.c (dlang_identifier): Prefix mangled init symbols
	with `initializer for'.
	* testsuite/demangle-expected: Update tests.

	* d-demangle.c (dlang_call_convention_p): Move declaration
	before dlang_type.
	(dlang_type): Handle function types.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_parse_real): Remove stack buffer, write
	the demangled hexadecimal directly to string.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_hexdigit): New function.
	(ascii2hex): Remove function.
	(dlang_parse_string): Update to call dlang_hexdigit.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (strtol): Remove declaration.
	Updated all callers to use dlang_number.
	(dlang_number): New function.
	(dlang_value): Moved check for ISDIGIT into dlang_parse_integer.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_parse_symbol): Remove function.
	(dlang_parse_qualified): New function.
	(dlang_parse_mangle): New function.
	(dlang_type): Update to call dlang_parse_qualified.
	(dlang_identifier): Update to call either dlang_parse_qualified or
	dlang_parse_mangle.
	(dlang_type_modifier_p): Remove function.
	(dlang_call_convention_p): Don't allow type modifiers in mangle.
	(dlang_template_args): Update to call dlang_identifier.
	(dlang_demangle): Update to call dlang_parse_mangle.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_value): Add comment explaining why cases for
	digits are required.
	* testsuite/d-demangle-expected: Update integer value tests.

	* d-demangle.c (dlang_parse_symbol): Skip over anonymous symbols.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_identifier): Handle template constraint symbols.
	(dlang_parse_template): Only advance if template symbol prefix is
	followed by a digit.
	* testsuite/d-demangle-expected: Add tests.

	* d-demangle.c (dlang_attributes): Handle scope attributes.
	* testsuite/d-demangle-expected: Add tests.