Add -x option (like in gcc).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50750 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvmc2/CompilationGraph.h b/tools/llvmc2/CompilationGraph.h
index 72cde9a..4692e51 100644
--- a/tools/llvmc2/CompilationGraph.h
+++ b/tools/llvmc2/CompilationGraph.h
@@ -165,7 +165,8 @@
                            const llvm::sys::Path& TempDir) const;
 
     // Find head of the toolchain corresponding to the given file.
-    const Node* FindToolChain(const llvm::sys::Path& In) const;
+    const Node* FindToolChain(const llvm::sys::Path& In,
+                              const std::string* forceLanguage) const;
 
     // Sort the nodes in topological order.
     void TopologicalSort(std::vector<const Node*>& Out);