PR c++/11547
* cp-tree.h (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P): New
macro.
(DECL_PRETTY_FUNCTION_P): Use VAR_DECL_CHECK.
* decl.c (duplicate_decls): Merge
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P.
* parser.c (cp_parser_postfix_expression): Adjust call to
cp_parser_initializer_list and
cp_parser_parenthesized_expression_list.
(cp_parser_parenthesized_expression_list): Add non_constant_p.
(cp_parser_new_placement): Adjust call to
cp_parser_parenthesized_expression_list.
(cp_parser_direct_new_declarator): Likewise.
(cp_parser_conditional_expression): Remove.
(cp_parser_constant_expression): Parse an assignment-expression,
not a conditional-expression.
(cp_parser_simple_declaration): Resolve expression/declaration
ambiguity more quickly.
(cp_parser_mem_initializer): Adjust call to
cp_parser_parenthesized_expression_list.
(cp_parser_init_declarator): Keep track of whether or not the
initializer is a constant-expression.
(cp_parser_initializer): Add non_constant_p parameter.
(cp_parser_initializer_clause): Likewise.
(cp_parser_initializer_list): Likewise.
(cp_parser_attribute_list): Adjust call to
cp_parser_parenthesized_expression_list.
(cp_parser_functional_cast): Likewise.
* pt.c (tsubst_decl): Copy
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P.
(tsubst_expr): Tweak use of DECL_PRETTY_FUNCTION_P.
* semantics.c (finish_id_expression): Use
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P.
PR c++/11547
* g++.dg/parse/constant3.C: New test.
* g++.dg/parse/crash7.C: Likewise.