[clang-tidy] Check if grand-..parent's virtual method was called instead of overridden parent's.

class A {...int virtual foo() {...}...}; 
class B: public A {...int foo() override {...}...}; 
class C: public B {...int foo() override {... A::foo()...}};
                                              ^^^^^^^^ warning: qualified name A::foo refers to a member overridden in subclass; did you mean 'B'? [bugprone-parent-virtual-call] 

Differential Revision: https://reviews.llvm.org/D44295

llvm-svn: 329448