Build error: 'GetMap' is a protected member of 'SwAccessibleContext'

With Ubuntu 17.04 x86-64, after commit: 
https://cgit.freedesktop.org/libreoffice/core/commit/sw/source/core/access/accmap.cxx?id=c99f72bebdce6d294eb47e070fa1397a98ba2087

sw: fix a11y crash on double Dispose

I'm getting the following build error


[CXX] sw/source/core/access/accmap.cxx
[CXX] sw/source/core/access/accnotextframe.cxx
[CXX] sw/source/core/access/accnotexthyperlink.cxx
[CXX] sw/source/core/access/accpage.cxx
[CXX] sw/source/core/access/accpara.cxx
/sw/source/core/access/accmap.cxx:2393:31: error: 'GetMap' is a protected member of 
'SwAccessibleContext'
                if (xAccImpl->GetMap()) // not if disposed by FireEvents()
                    ~~~~~~~~~~^~~~~~
/sw/source/core/access/acccontext.hxx:115:22: note: declared protected here
    SwAccessibleMap *GetMap() { return m_pMap; }
                     ^
1 error generated.
/solenv/gbuild/LinkTarget.mk:288: recipe for target 
'/workdir/CxxObject/sw/source/core/access/accmap.o' failed
make[1]: *** [/workdir/CxxObject/sw/source/core/access/accmap.o] Error 1
make[1]: *** Waiting for unfinished jobs....
Makefile:264: recipe for target 'build' failed



luke@luke-X555LAB:~/u64/lo/core$ clang --version
clang version 5.0.0 (trunk 298676)
Target: x86_64-unknown-linux-gnu

luke@luke-X555LAB:~/u64/lo/core$ cat autogen.input 
--disable-firebird-sdbc
--without-export-validation
CC=clang
CXX=clang++

$ git revert c99f72bebdce6d294eb47e070fa1397a98ba2087

allows the build to complete without errors