Remove remaining traces of llvm::Type from cling::Value.
Remove now unused Interpreter::getLLVMType().
Revert "Expose QualType to llvm::Type codegen-ing."

This reverts commit f3bbbd62d108dafc1cda690d455b808b386942e2.
Not needed anymore as we don't use llvm::ExecutionEngine::runFunction() anymore.
Remove now unused llvm::Type from cling::Value + dependencies.