[Bug target/78077] New: gcc 6.2.0 fails to link temacs from emacs-25.1 using the Xcode 8 linker

["howarth.at.gcc at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78077

            Bug ID: 78077
           Summary: gcc 6.2.0 fails to link temacs from emacs-25.1 using
                    the Xcode 8 linker
           Product: gcc
           Version: 6.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: howarth.at.gcc at gmail dot com
  Target Milestone: ---

The gcc 6.2.0 release fails to link temacs in the build of emacs-25.1 on
x86_64-apple-darwin15 using the Xcode 8 linker. Configuring a build as...

../configure --without-ns CC=/sw/bin/gcc-fsf-6 CXX=/sw/bin/g++-fsf-6
CPPFLAGS="-I/sw/include" LDFLAGS="-L/sw/lib"

results in a build that fails at...

  CCLD     temacs
0  0x1097875cc  __assert_rtn + 144
1  0x10979a9df 
mach_o::relocatable::Parser<x86_64>::parse(mach_o::relocatable::ParserOptions
const&) + 3195
2  0x109792536  mach_o::relocatable::Parser<x86_64>::parse(unsigned char
const*, unsigned long long, char const*, long, ld::File::Ordinal,
mach_o::relocatable::ParserOptions const&) + 342
3  0x1097d3bac  ld::tool::InputFiles::makeFile(Options::FileInfo const&, bool)
+ 824
4  0x1097d640b  ld::tool::InputFiles::parseWorkerThread() + 495
5  0x7fff99bde99d  _pthread_body + 131
6  0x7fff99bde91a  _pthread_body + 0
A linker snapshot was created at:
        /tmp/temacs-2016-09-22-161008.ld-snapshot
ld: Assertion failed: (cfiStartsArray[i] != cfiStartsArray[i-1]), function
parse, file
/Library/Caches/com.apple.xbs/Sources/ld64/ld64-274.1/src/ld/parsers/macho_relocatable_file.cpp,
line 1893.
collect2: error: ld returned 1 exit status