Fix some failures in targets on available_externally functions,
this fixes a crash on CodeGen/Generic/externally_available.ll
on ppc hosts.  Thanks to Nicholas L for pointing this out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69333 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index fc99f50..8b2473b 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -116,6 +116,11 @@
     virtual bool doInitialization(Module &M);
 
     bool runOnFunction(Function &F) {
+     // Do not codegen any 'available_externally' functions at all, they have
+     // definitions outside the translation unit.
+     if (F.hasAvailableExternallyLinkage())
+       return false;
+
       LI = &getAnalysis<LoopInfo>();
 
       // Get rid of intrinsics we can't handle.