Split the addImage method for ELF into two branches for ELF32 and for
ELF64 depending on the value stored in the identifier of the image.
Most of the code of the previous function moves into readELFSections,
which is build similar to the already existing readMachOSections. The
code is only modified to use the types from the template parameter.
This fixes a couple of reflection tests in Android armv7 (and I suppose
it should also fix the same problem in other 32 bits platforms which use
ELF).
ec86064209