Create and use an llvm.eh.sjlj.functioncontext intrinsic.

This intrinsic is used to pass the index of the function context to the back-end
for further processing. The back-end is in charge of filling in the rest of the
entries.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140676 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp
index baa70b9..9749a7e 100644
--- a/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/lib/CodeGen/SjLjEHPrepare.cpp
@@ -721,6 +721,12 @@
   AllocaInst *FuncCtx =
     new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin());
 
+  // Store a pointer to the function context so that the back-end will know
+  // where to look for it.
+  CallInst::Create(Intrinsic::getDeclaration(F.getParent(),
+                                            Intrinsic::eh_sjlj_functioncontext),
+                   FuncCtx, "", EntryBB->getTerminator());
+
   // Fill in the function context structure.
   Value *Idxs[2];
   Type *Int32Ty = Type::getInt32Ty(F.getContext());