[Bug bootstrap/59447] --with-dwarf2 is not propagated correctly, will always create dwarf4 by default

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59447

--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot 
com> ---
This is a documentation bug - the installation manual should make clear 
that "DWARF 2" in the description of this option means DWARF 2 or later, 
as appropriate for the target, as opposed to (for example) STABS.