[Clang] Don't warn if deferencing void pointers in unevaluated context

After https://reviews.llvm.org/D134461, Clang will diagnose a warning if
trying to deference void pointers in C mode. However, this causes a lot
of noises when compiling a 5.19.11 Linux kernel.

This patch reduces the warning by marking deferencing void pointers in
unevaluated context OK, like `sizeof(*void_ptr)`, `typeof(*void_ptr)`
and etc.

Fixes https://github.com/ClangBuiltLinux/linux/issues/1720



Signed-off-by: Jun Zhang <jun@junz.org>

Differential Revision: https://reviews.llvm.org/D134702