Revert r306103: "PR26195: Set correct NestedNameSpecifierLoc for the

dependent initializer"

It caused buildbot failures such as this one:
http://bb.pgr.jp/builders/test-clang-msc-x64-on-i686-linux-RA/builds/3777/steps/test_clang/logs/Clang%20%3A%3A%20Index__ctor-init-source-loc.cpp

llvm-svn: 306111