Addressing must be PC-relative, so adapt the approach from the other
nova_x86_32 syscall bindings (description by @ssumpf):
Use call to push the current IP on the stack and add the distance of
label 0 and label 1 in order to determine the return address, which
NOVA requires in edx.
The bug only showed up with "-O0" in libc.lib.so in form of a unwanted
text relocation.
Fixes#1721
Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:
repos/base/include/spec
repos/base/mk/spec
repos/base/lib/mk/spec
repos/base/src/core/spec
...
Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.
Fix#1673
