Add bmk_ctassert() for compile-time assertions.

Retire bmk_page{size,shift}, use BMK_PCPU_PAGE_{SIZE,SHIFT}.

Latter are compile-time constants.

explicitly allocate mainstack

+ bmk_{round,trunc}_page()

add bmk_pageshift

I thought I added this already ???

Use __builtin_expect() in bmk_assert()

For a trivial measurement loop giving the branch hint actually appears
to produce slower code than if it's not given, but I think we should
generally trust the compiler. At least using the wrong __builtin_expect
produces slower code ;)

pass stack size to bmk-core as page shift instead of size

Replace bmk_ops function pointers with regular functions.

Prefix those function bmk_platform, e.g. bmk_platform_halt()

add bmk_assert

Add copyright/license.

Better late than never ...

add files missed in previous commit