(is_mapped_only, cris_dump_map): New functions.
(cris_break_13_handler) <case TARGET_SYS_mmap2>: Handle more flags
and prot combinations and a non-zero page-offset. If
TARGET_MAP_FIXED, unmap pages before mapping them.
<case TARGET_SYS_mprotect>: When checking, allow any length
argument. Don't actually do anything.
<case TARGET_SYS_writev>: New case.