[MSan] Add flag to disable use-after-dtor.

Summary: Flag is -fno-sanitize-use-after-dtor.

Reviewers: vitalybuka, eugenis, kcc

Reviewed By: vitalybuka, eugenis

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D37867

llvm-svn: 313314
diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index a6cc67b..bf8d062 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -489,7 +489,9 @@
       }
     }
     MsanUseAfterDtor =
-        Args.hasArg(options::OPT_fsanitize_memory_use_after_dtor);
+        Args.hasFlag(options::OPT_fsanitize_memory_use_after_dtor,
+                     options::OPT_fno_sanitize_memory_use_after_dtor,
+                     false);
     NeedPIE |= !(TC.getTriple().isOSLinux() &&
                  TC.getTriple().getArch() == llvm::Triple::x86_64);
   }