The symbol downloaders fail with core dumps created with gdb

[mikem8361]

Coredumps created with gdb have garbage for the ELF module headers. It seems fairly random because some native modules and some don't. lldb and gdb don't have a problem loading these dumps without any problems.

Detecting this and display a warning or error message that this dump was created with gdb would be good.

This can be fixed in the file format for ELF core dumps by creating a special derived ELF file class that uses the core dumps header info by returning the proper bitness, endianess and module type.

This makes distinguishing ELF modules from the PE modules in the core dump more difficult. The signature check for PE's would have to be first.

[mikem8361]

Looks like there is the same issue with gcore generated dumps.