The use of an unreliable test for relocatability effectively broke
runtime_loader's support for non-position-independent executables, as it
would insist on randomly positioning these files' segments in memory
anyway causing the program to quickly crash.
With this change runtime_loader uses the object type specified in the
file's header to determine whether its segments can be safely relocated,
restoring support for non-PI executables.
Fixes#12427.
Signed-off-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
078b88b12d