lit.cfg: fix a bug in simulator target

Author: Joe Shajrawi

test/lit.cfg

@@ -642,6 +642,8 @@ def use_interpreter_for_simple_runs():
 
 target_specific_module_triple = config.variant_triple
 
+config.target_run = ""
+
 if run_vendor == 'apple':
  target_specific_module_triple = '{}-apple-{}'.format(
  { 'aarch64': 'arm64', 'amd64': 'x86_64' }.get(run_cpu, run_cpu),
@@ -1356,7 +1358,8 @@ if not kIsWindows:
 "/usr/bin/env "
 "DYLD_LIBRARY_PATH='{0}' " # Apple option
 "LD_LIBRARY_PATH='{0}' " # Linux option
-.format(target_stdlib_path))
+"SIMCTL_CHILD_DYLD_LIBRARY_PATH='{0}' " # Simulator option
+.format(target_stdlib_path)) + config.target_run
 else:
 os_stdlib_path = ''
 if run_vendor == 'apple':
@@ -1368,7 +1371,8 @@ if not kIsWindows:
 "/usr/bin/env "
 "DYLD_LIBRARY_PATH='{0}' " # Apple option
 "LD_LIBRARY_PATH='{0}' " # Linux option
-.format(all_stdlib_path))
+"SIMCTL_CHILD_DYLD_LIBRARY_PATH='{0}' " # Simulator option
+.format(all_stdlib_path)) + config.target_run
 
 #
 # When changing substitutions, update docs/Testing.rst.