add more foo_checking_assert macros lisp.h: Add structure_checking_assert(), gc_checking_assert(), etc. for all types of error-checking. Also FOO_checking_assert_with_message() and inline_FOO_checking_assert() -- the latter for use in an inline function where you want the calling function's line/file to be reported (requires some conspiracy with the function itself). Add disabled_assert(), disabled_assert_at_line(), disabled_assert_with_message(), for what to do when an assert is disabled. Formerly, we used to do ((void) 0), but now we do ((void) x), so the variable appears used and any side effects of the expression do get done. In Unicode-internal, the standard assert() uses this, but not yet in this workspace.