[test] Enable LeakSanitizer on 64-bit Darwin ASan llvm builds

Summary:
Also disables leak checking on lto tests, due to many leaks reported
in the system's ld64.

Reviewers: kcc, pcc, bogner, kubamracek

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D37781

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314535 91177308-0d34-0410-b5e6-96231b3b80d8

test/tools/lto/lit.local.cfg

@@ -1,2 +1,6 @@
 if not ('ld64_plugin' in config.available_features and 'X86' in config.root.targets):
-   config.unsupported = True
+    config.unsupported = True
+
+# These tests invoke ld64 from the system, which is not leak-free
+if "Address" in config.llvm_use_sanitizer:
+    config.environment['ASAN_OPTIONS'] = 'detect_leaks=0'

utils/lit/lit/llvm/config.py

@@ -75,6 +75,9 @@ class LLVMConfig(object):
             features.add("long_tests")
 
         if target_triple:
+            if re.match(r'^x86_64.*-apple', target_triple):
+                if 'address' in sanitizers:
+                    self.with_environment('ASAN_OPTIONS', 'detect_leaks=1', append_path=True)
             if re.match(r'^x86_64.*-linux', target_triple):
                 features.add("x86_64-linux")
             if re.match(r'.*-win32$', target_triple):