Darwin, configury : Allow for specification and detection of dsymutil.

Darwin, configury : Allow for specification and detection of dsymutil.

In order to enable DWARF versions > 2 we need a sufficiently modern
version of dsymutil (in addition to the assembler / linker).  This
allows the user to configure a different path from the installed one.

In addition, there are several sources of dsymutil so we differentiate
these in order to be get accurate version information.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
gcc/ChangeLog:

	* configure.ac: Handle --with-dsymutil in the same way as we
	do for the assembler and linker.  (DEFAULT_DSYMUTIL): New.
	Extract the type and version for the dsymutil configured or
	found by the default searches.
	* config.in: Regenerated.
	* configure: Regenerated.
	* collect2.c (do_dsymutil): Handle locating dsymutil in the
	same way as for the assembler and  linker.
	* config/darwin.h (DSYMUTIL): Delete.
	* gcc.c: Report a configured dsymutil correctly.
	* exec-tool.in: Allow for dsymutil.

ChangeLog:

	* Makefile.def: Add dsymutil defs.
	* Makefile.in: Regenerated.
	* Makefile.tpl: Add dsymutil to flags.
	* configure: Regenerated.
	* configure.ac: Add dsymutil to target and build recipes.