tools/llvm: Do not build with symbols

Do not build clang and llvm libraries with debug symbols, when built as
a cross-compilation tool.

This saves a lot of space (about 4G), and hopefully also some
compilation time.

Change-Id: Ifeb91d6932d667fa901a8efe1a95a922e6f6ba98
vm: allow split of mem_anon_contig region

	. so that memory of such regions can be deallocated in any order

Change-Id: I34013d6085cf19a482412cf9bed6b7f96e60e1e6
Make the kernel less chatty

Change some messages from always printed to varying level of the "verbose"
argument.

Change-Id: I6899268aa895c66e72806ca4d02bb53a0e4ea785