gdb

gdb
	PR c++/9680:
	* c-exp.y (REINTERPRET_CAST, DYNAMIC_CAST, STATIC_CAST)
	(CONST_CAST): New tokens.
	(exp): Add new productions.
	(ident_tokens): Add const_cast, dynamic_cast, static_cast, and
	reinterpret_cast.
	(is_cast_operator): New function.
	(yylex): Handle cast operators specially.
	* eval.c (evaluate_subexp_standard) <UNOP_DYNAMIC_CAST,
	UNOP_REINTERPRET_CAST>: New cases.
	* expprint.c (print_subexp_standard): Likewise.
	(op_name_standard): Likewise.
	(dump_subexp_body_standard): Likewise.
	* parse.c (operator_length_standard): Likewise.
	* expression.h (enum exp_opcode): New constants UNOP_DYNAMIC_CAST,
	UNOP_REINTERPRET_CAST.
	* gdbtypes.c (class_types_same_p): New function.
	(is_ancestor): Use it.
	(is_public_ancestor): New function.
	(is_unique_ancestor_worker): Likewise.
	(is_unique_ancestor): Likewise.
	* gdbtypes.h (class_types_same_p, is_public_ancestor)
	(is_unique_ancestor): Declare.
	* valops.c (value_reinterpret_cast): New function.
	(dynamic_cast_check_1): Likewise.
	(dynamic_cast_check_2): Likewise.
	(value_dynamic_cast): Likewise.
	* value.h (value_reinterpret_cast, value_dynamic_cast): Declare.
gdb/testsuite
	PR c++/9680:
	* gdb.cp/casts.cc: Add new classes and variables.
	* gdb.cp/casts.exp: Test new operators.