Add a possible underscore before the wrappers to the output expectations for Darwin

llvm-svn: 167610
diff --git a/compiler-rt/lib/asan/lit_tests/strncpy-overflow.cc b/compiler-rt/lib/asan/lit_tests/strncpy-overflow.cc
index d3c66da..9381f13 100644
--- a/compiler-rt/lib/asan/lit_tests/strncpy-overflow.cc
+++ b/compiler-rt/lib/asan/lit_tests/strncpy-overflow.cc
@@ -24,7 +24,7 @@
   strncpy(short_buffer, hello, 10);  // BOOM
   // CHECK: {{WRITE of size 1 at 0x.* thread T0}}
   // CHECK-Linux: {{    #0 0x.* in .*strncpy}}
-  // CHECK-Darwin: {{    #0 0x.* in wrap_strncpy}}
+  // CHECK-Darwin: {{    #0 0x.* in _?wrap_strncpy}}
   // CHECK: {{    #1 0x.* in _?main .*strncpy-overflow.cc:24}}
   // CHECK: {{0x.* is located 0 bytes to the right of 9-byte region}}
   // CHECK: {{allocated by thread T0 here:}}