[lldb] Kill the inferior instead of detaching during test suite runs

Kill (rather than detach) form the inferior if debugserver loses its
connection to lldb to prevent zombie processes.

Differential revision: https://reviews.llvm.org/D92908
diff --git a/lldb/test/Shell/lit-lldb-init.in b/lldb/test/Shell/lit-lldb-init.in
index 0fd7cbf..6d3b5fe 100644
--- a/lldb/test/Shell/lit-lldb-init.in
+++ b/lldb/test/Shell/lit-lldb-init.in
@@ -5,3 +5,4 @@
 settings set symbols.clang-modules-cache-path "@LLDB_TEST_MODULE_CACHE_LLDB@"
 settings set target.auto-apply-fixits false
 settings set target.inherit-tcc true
+settings set target.detach-on-error false