cp-demangle.c (d_print_comp): Don't push more than one of the same CV-qualifier on the top of the stack.
* cp-demangle.c (d_print_comp) [RESTRICT, VOLATILE, CONST]: Don't
push more than one of the same CV-qualifier on the top of the
stack.
(d_print_comp) [ARRAY_TYPE]: If the array itself is CV-qualified,
move the CV-qualifiers to apply to the element type instead.
(d_print_array_type): When checking the modifiers, keep looking
past ones which have been printed already.
* testsuite/demangle-expected: Add three test cases.