Revert "[Tooling/Inclusion] Handle std::get symbol."

Revert "[Tooling/Inclusion] Handle std::get symbol."

This reverts commit cbcb3eef70def3509bdffd4fe1ebfb6422afeaa2.

Causing many clangd test breakages, similar to:

error: no matching constructor for initialization of 'llvm::SmallVector<clang::tooling::stdlib::Header>'
                : llvm::SmallVector<clang::tooling::stdlib::Header>(
                  ^