[analyzer] Use the static type for a virtual call if the dynamic type is worse.

reinterpret_cast does not provide any of the usual type information that
static_cast or dynamic_cast provide -- only the new type. This can get us
in a situation where the dynamic type info for an object is actually a
superclass of the static type, which does not match what CodeGen does at all.
In these cases, just fall back to the static type as the best possible type
for devirtualization.

Should fix the crashes on our internal buildbot.

llvm-svn: 163644