add enough support for indirect branch for the feature test to pass
(assembler,asmprinter, bc reader+writer) and document it.  Codegen
currently aborts on it.

llvm-svn: 85274
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
index 7470551..9aca707 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
@@ -49,6 +49,7 @@
 class GCFunctionInfo;
 class ICmpInst;
 class IntToPtrInst;
+class IndBrInst;
 class InvokeInst;
 class InsertElementInst;
 class InsertValueInst;
@@ -448,6 +449,7 @@
   void visitRet(ReturnInst &I);
   void visitBr(BranchInst &I);
   void visitSwitch(SwitchInst &I);
+  void visitIndBr(IndBrInst &I);
   void visitUnreachable(UnreachableInst &I) { /* noop */ }
 
   // Helpers for visitSwitch