Subzero: Fix lit and cross tests broken in f8b4cc8.

src/IceGlobalInits.h

Index: src/IceGlobalInits.h
diff --git a/src/IceGlobalInits.h b/src/IceGlobalInits.h
index 8b060419652aab2eaba3c1e32468a69f3c7bf129..4c51606c6419f9aa13428c405a3481baa9c9eb53 100644
--- a/src/IceGlobalInits.h
+++ b/src/IceGlobalInits.h
@@ -286,9 +286,15 @@ public:
   }
 
   bool getSuppressMangling() const final {
+    if (ForceSuppressMangling)
+      return true;
     return isExternal() && !hasInitializer();
   }
 
+  void setSuppressMangling() {
+    ForceSuppressMangling = true;
+  }
+
 private:
   // list of initializers for the declared variable.
   InitializerListType Initializers;
@@ -296,11 +302,13 @@ private:
   uint32_t Alignment;
   // True if a declared (global) constant.
   bool IsConstant;
+  // If set to true, force getSuppressMangling() to return true.
+  bool ForceSuppressMangling;
 
   VariableDeclaration()
       : GlobalDeclaration(VariableDeclarationKind,
                           llvm::GlobalValue::InternalLinkage),
-        Alignment(0), IsConstant(false) {}
+        Alignment(0), IsConstant(false), ForceSuppressMangling(false) {}
 };
 
 template <class StreamType>