[pr/17940] bfd/dwarf2.c: fix overflow bug in .dwarf_line

[Nicholas Clifton]

Hi DJ,

> If you have an unlinked object compiled with -ftext-sections,
> you get:
>
> RELOCATION RECORDS FOR [.debug_line]:
> OFFSET   TYPE              VALUE
> 00000000 R_MSP430_ABS32    .debug_line_end-0x00000004
>
> with .debug_line_end undefined (i.e. has a value of zero), which
> results in -4 (0xfffffffc) being stored during "simple_reloc".  This
> is interpreted as a very large positive number.  This patch checks for
> that special case, and arbitrary overflow cases.  OK?

Can you provide a testcase to go along with this patch please ?

Cheers
   Nick