re PR c++/41774 (ice: vector VEC(visibility,base) pop domain error, in pop_visibility at c-pragma.c:757)
PR c++/41774
* c-pragma.c (visstack): Change into vector of ints rather than
enum symbol_visibility.
(push_visibility): Add kind argument, push default_visibility together
with kind.
(pop_visibility): Add kind argument, return true if successful, fail
if visibility stack is empty or if stack top is of different kind.
(handle_pragma_visibility): Don't check length of visstack, instead
call pop_visibility and issue diagnostics if it failed. Pass 0
as last argument to push_visibility and pop_visibility.
* c-pragma.h (push_visibility): Add kind argument.
(pop_visibility): Likewise. Return bool instead of void.
* name-lookup.c (handle_namespace_attrs): Pass 1 as last argument to
push_visibility.
* parser.c (cp_parser_namespace_definition): Pass 1 as argument to
pop_visibility.
* rtti.c (push_abi_namespace): Pass 2 as last argument to
push_visibility.
(pop_abi_namespace): Pass 2 as argument to pop_visibility.
* g++.dg/ext/visibility/namespace3.C: New test.
From-SVN: r153805
