Introduce model of global initializers in Subzero.

src/IceConverter.h

Index: src/IceConverter.h
diff --git a/src/IceConverter.h b/src/IceConverter.h
index 049c03668741d23e5cfabc0fd0a85f9d2ce3094f..ecb76b3cd13a55c4e39fc524f8f9a38d6b7d9d7a 100644
--- a/src/IceConverter.h
+++ b/src/IceConverter.h
@@ -26,6 +26,7 @@ class Converter : public Translator {
 public:
   Converter(llvm::Module *Mod, GlobalContext *Ctx, const Ice::ClFlags &Flags)
       : Translator(Ctx, Flags), Mod(Mod) {}
+
   /// Converts the LLVM Module to ICE. Sets exit status to false if successful,
   /// true otherwise.
   void convertToIce();
@@ -34,6 +35,10 @@ private:
   llvm::Module *Mod;
   // Converts functions to ICE, and then machine code.
   void convertFunctions();
+
+  // Converts globals to ICE, and then machine code.
+  void convertGlobals(llvm::Module *Mod);
+
   Converter(const Converter &) = delete;
   Converter &operator=(const Converter &) = delete;
 };