[LLDB] Enable LLDB testing for macOS toolchain

Author: shahmishal

utils/build-presets.ini

@@ -960,9 +960,6 @@ mixin-preset=
 
 dash-dash
 
-# rdar://problem/31480188
-skip-test-lldb
-
 swift-install-components=compiler;clang-builtin-headers;stdlib;sdk-overlay;license;sourcekit-xpc-service;swift-remote-mirror;swift-remote-mirror-headers
 llvm-install-components=libclang;libclang-headers