Add to the split module utility an SCC based method which allows not to globalize any local variables.
    
    Summary:
    Currently llvm::SplitModule as the first step globalizes all local objects, which might not be desirable in some scenarios.
    This change adds a new flag to llvm::SplitModule that uses SCC approach to search for a balanced partition without the need to externalize symbols.
    Such partition might not be possible or fully balanced for a given number of partitions, and is a function of the module properties (global/local dependencies within the module).
    
    Joint development Tobias Edler von Koch (tobias@codeaurora.org) and Sergei Larin (slarin@codeaurora.org)
    
    Subscribers: llvm-commits, joker.eph
    
    Differential Revision: http://reviews.llvm.org/D16124

llvm-svn: 258083
diff --git a/llvm/tools/llvm-split/llvm-split.cpp b/llvm/tools/llvm-split/llvm-split.cpp
index 059770f..04ca193 100644
--- a/llvm/tools/llvm-split/llvm-split.cpp
+++ b/llvm/tools/llvm-split/llvm-split.cpp
@@ -35,6 +35,10 @@
 static cl::opt<unsigned> NumOutputs("j", cl::Prefix, cl::init(2),
                                     cl::desc("Number of output files"));
 
+static cl::opt<bool>
+    PreserveLocals("preserve-locals", cl::Prefix, cl::init(false),
+                   cl::desc("Split without externalizing locals"));
+
 int main(int argc, char **argv) {
   LLVMContext &Context = getGlobalContext();
   SMDiagnostic Err;
@@ -61,7 +65,7 @@
 
     // Declare success.
     Out->keep();
-  });
+  }, PreserveLocals);
 
   return 0;
 }