We were incorrectly assuming that the mapped .text segment for an ELF
image was always at the base of the image mapping. Now that we have
.rodata mappings as well, it's possible for one of them to come before
the .text.
This enables further work on implementing KASLR by adding relocation
support to the pre-kernel and updating the kernel to be less dependent
on specific virtual memory layouts.
This removes all the hard-coded kernel base addresses from userspace
tools.
One downside for this is that e.g. Profiler no longer uses a different
color for kernel symbols when run as a non-root user.
This fixes an issue were some LibDebug objects (for example,
Dwarf::CompilationUnit) held a reference to their parent
Dwarf::DwarfInfo object, which was constructed on the stack and later
moved to the heap.
