bcc: Add option -emit-llvm

Change-Id: I98470c6573b216518f77d338f4659d5b9fbcc3d3
diff --git a/tools/bcc/Main.cpp b/tools/bcc/Main.cpp
index fa80d95..d20e49b 100644
--- a/tools/bcc/Main.cpp
+++ b/tools/bcc/Main.cpp
@@ -72,6 +72,10 @@
               llvm::cl::value_desc("output path"),
               llvm::cl::init("."));
 
+llvm::cl::opt<bool>
+OptEmitLLVM("emit-llvm",
+            llvm::cl::desc("Emit an LLVM-IR version of the generated program"));
+
 #ifdef TARGET_BUILD
 const std::string OptTargetTriple(DEFAULT_TARGET_TRIPLE_STRING);
 #else
@@ -201,7 +205,7 @@
 
   bool built = RSCD.build(context, OptOutputPath.c_str(),
       OptOutputFilename.c_str(), bitcode, bitcodeSize,
-      OptBCLibFilename.c_str(), NULL);
+      OptBCLibFilename.c_str(), NULL, OptEmitLLVM);
 
   if (!built) {
     return EXIT_FAILURE;