[PATCH, Darwin, config] Check for DWARF debug line support with otool.

[Jeff Law]

On 12/23/18 4:53 AM, Iain Sandoe wrote:
> Hi,
> 
> This corrects a long-standing misconfiguration for Darwin.
> The assembler supports the “.file” and “.loc” directives, but
> the GCC configury was not detecting this because it was 
> using objdump, which does not exist on most Darwin installations.
> 
> We added support for “otool” to GCC and now we can use that to
> make the check that’s done with objdump on ELF targets.
> 
> OK for trunk?
> Iain
> 
> gcc/
> 
> 	* configure.ac (dwarf2_debug_line): Check for the debug_line
> 	section using otool when there’s no objdump available.
> 	* configure: Regenerate.
OK
jeff