Hwasan reporting check for dladdr failing

Hwasan reporting check for dladdr failing

In `GetGlobalSizeFromDescriptor` we use `dladdr` to get info on the the
current address.  `dladdr` returns 0 if it failed.
During testing on Linux this returned 0 to indicate failure, and
populated the `info` structure with a NULL pointer which was
dereferenced later.

This patch checks for `dladdr` returning 0, and in that case returns 0
from `GetGlobalSizeFromDescriptor` to indicate failure of identifying
the address.

This occurs when `GetModuleNameAndOffsetForPC` succeeds for some address
not in a dynamically loaded library.  One example is when the found
"module" is '[stack]' having come from parsing /proc/self/maps.

Differential Revision: https://reviews.llvm.org/D91344