Merge ae64e8ae3e9a9dc832df1d7752dd977f85cf90ff into c71991ec5a914f77537f7243763f58eabb0bcb13
compilable to llvm r193280

getFirstDeclaration() was renamed to getFirstDecl() in r192900.
Thanks for the patch provided by Markus Trippelsdorf!
Replace VarDecl::getFirstDecl with VarDecl::getCanonicalDecl