[lldb] Make TSan errors fatal when running the test suite

Set the halt_on_error runtime flag to make TSan errors fatal when
running the test suite. For the API tests the environment variables are
set conditionally on whether the TSan is enabled. The Shell and Unit
tests don't have that logic but setting the environment variable is
harmless. For consistency, I've also mirrored the ASAN option
(detect_stack_use_after_return=1) for the Shell tests.

Differential revision: https://reviews.llvm.org/D157152