[stackprotector] Add in the stackprotector libcall.

We support this libcall on all platforms except for OpenBSD (See
lib/Codegen/StackProtector.cpp).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188193 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetLoweringBase.cpp b/lib/CodeGen/TargetLoweringBase.cpp
index b3711ad..55125bd 100644
--- a/lib/CodeGen/TargetLoweringBase.cpp
+++ b/lib/CodeGen/TargetLoweringBase.cpp
@@ -361,6 +361,13 @@
     Names[RTLIB::SINCOS_F128] = 0;
     Names[RTLIB::SINCOS_PPCF128] = 0;
   }
+
+  if (Triple(TM.getTargetTriple()).getOS() != Triple::OpenBSD) {
+    Names[RTLIB::STACKPROTECTOR_CHECK_FAIL] = "__stack_chk_fail";
+  } else {
+    // These are generally not available.
+    Names[RTLIB::STACKPROTECTOR_CHECK_FAIL] = 0;
+  }
 }
 
 /// InitLibcallCallingConvs - Set default libcall CallingConvs.