Merge pull request swiftlang#28096 from apple/shahmishal/5.1-update-lit-sim

[5.1] Update the simulator for lit test to use iPhone 8

Author: shahmishal

test/lit.cfg

@@ -118,11 +118,11 @@ def get_simulator_command(run_os, run_cpu, sdk_path):
             else:
                 return "simctl spawn --standalone 'iPhone 5'"
         else:
-            return "simctl spawn --standalone 'iPhone Xs'"
+            return "simctl spawn --standalone 'iPhone 8'"
     elif run_os == 'tvos':
         return "simctl spawn --standalone 'Apple TV 4K'"
     elif run_os == 'watchos':
-        return "simctl spawn --standalone 'Apple Watch Series 3 - 38mm'"
+        return "simctl spawn --standalone 'Apple Watch Series 4 - 44mm'"
     else:
         lit_config.fatal("Unknown simulator OS %r" % run_os)